The event, which began at 9 p.m. EDT Tuesday, offers Americans their most detailed look at a campaign that's dramatically changed since the last debate in June. In rapid fashion, President Joe Biden bowed out of the race after his disastrous performance, Trump survived an assassination attempt and bothsides chose their running mates.

It's the only debate that's been firmly scheduled and could be the only time voters see Harris and Trump go head-to-head before the November general election.

The debate has no audience, no written notes, and no live mics when candidates aren't speaking, according to rules the host network ABC News shared.

Follow the AP's Election 2024 coverage at: https://apnews.com/hub/election-2024.

Here's the latest:

Trump again distances himself from Project 2025

Trump is again distancing himself from Project 2025, the Heritage Foundation project crafted by dozens of his former administration officials.

"I haven't read it. I don't want to read it, purposefully. I'm not going to read it," he says.

Democrats have made the deeply conservative proposals a centerpiece of their attacks against Trump.

Harris focuses on middle class in first answer; Trump pivots to immigration

With the White House under pressure on the economy, Harris said she was "raised as a middle class kid" and would be focused on creating an "opportunity economy."

She also sharply criticized Trump for policies that she said would increase costs for Americans.

Trump rejected the description, and he said he would focus on tariffs on imports from foreign countries.

He also swiftly shifted focus to immigration, saying people were "pouring into the country."

First question of the debate is on the economy

Many voters say it's the top issue for them in this election, and the economy is the first question during the Harris-Trump debate.

Americans are slightly more likely to trust Trump over Harris when it comes to handling the economy, according to an AP-NORC poll from August.

Views about the economy aren't especially rosy. About 6 in 10 U.S. adults say economic conditions in the country are "getting worse," according to a recent Gallup poll. And slightly fewer than half (45%) rate the U.S. economy as "poor" while 31% describe it as "only fair." About one-quarter call it excellent or good.

By one measure, Americans are not better or worse off than four years ago. Earlier Tuesday, the Census Bureau released an annual report that showed inflation-adjusted U.S. median household income in 2023 rose for the first time since 2019 to $80,610 -- about the same as it was four years ago, in 2019.

The Harris-Trump debate has begun

It may be the one and only time Harris and Trump meet onstage, and their presidential debate is now underway.

The Democratic and Republican nominees have taken the stage at the National Constitution Center in Philadelphia.

For the next 90 minutes, Harris and Trump will be going one-on-on to make their arguments to American voters. They'll be standing behind podiums about 6-8 feet apart in a small, blue-lit amphitheater.

As with the Biden-Trump debate earlier this summer, there's no live audience in the room. That means that there will be no rowdy applause, cheers or jeers.

The debate is hosted by ABC News.

Harris and Trump shook hands as they took the stage for their debate.

CNN's Anderson Cooper: 'We had no idea what was going to happen'

CNN's Anderson Cooper acknowledges that no one could have known what was about to happen in the previous debate in June -- and that this one's the same.

"We were all thinking, `This is going to be a really consequential debate.? But we had no idea what was going to happen on that stage," Cooper said minutes before the Trump-Harris debate began.

Joe Biden's performance in the debate started a sequence of events that led to him withdrawing from the race weeks later.

Cooper says the same's true of tonight: No one knows.

National Constitution Center gussied up for debate

The stage and lighting are secondary to what Trump and Harris have to say, but debate organizers made sure the National Constitution Center is looking its best for tonight's debate.

The arena is bathed in blue light. The candidates will face a giant screen with the countdown clock set at 2:00. The set is decorated with images of the constitutional text, with a "We the People" above the lecterns.

Hundreds gather to watch the debate on a huge screen

At Salem Baptist Church of Abington, a historically Black church in the Philadelphia suburbs, hundreds of people gathered outside on the church's football field to watch the debate on a 33-foot screen.

It was a festival atmosphere beforehand, with food trucks, Boy Scouts playing cornhole on American-flag themed boards, the Montgomery County voter services department offering to register voters and a DJ blasting music at the event dubbed "Vote-A-Palooza!"

"How's this for Americana?" said the church pastor, the Rev. Marshall Mitchell.

Tonight's debate could be longer than planned

Tonight's Harris-Trump debate is set to go 90 minutes, but don't be surprised if it goes a little long.

Trump and Biden's debate in July hosted by CNN was also scheduled for 90 minutes, but ended up running about eight minutes long.

ABC says that tonight's debate includes two commercial breaks, so it might not be a bad idea to make that bathroom pit stop now.

Who are the debate moderators?

Most of the focus during the debate is on the candidates, but with no audience, there's sure to be plenty of attention on the moderators, too.

The Harris-Trump debate is happening on ABC News and is hosted by two of its news personalities.

David Muir's "World News Tonight" has led the evening news ratings for eight years, making him effectively America's most popular newscaster. Many nights "World News Tonight" has a bigger audience than anything on prime-time television.

Linsey Davis has a lower profile, and many will be seeing her in action on Tuesday night for the first time. She hosts ABC's nightly streaming newscast, fills in for Muir and has moderated presidential nominating debates in the past.

Trump had repeatedly sown doubt he would participate in ABC News' debate, arguing that he agreed to do so when Biden, not Harris, was Democrats' nominee. The Republican nominee has repeatedly criticized the network, targeting network political journalists George Stephanopoulos and Jonathan Karl specifically.

Israel-Hamas war protesters gather outside debate venue

Demonstrators are protesting the Israel-Hamas war in Philadelphia where the presidential debate is scheduled Tuesday evening.

Scores of people lined the streets shouting: "Justice is our demand," carrying banners and flags and holding signs that read "arms embargo now."

Philadelphia has been a key venue in Harris' rise in presidential politics

In November 2020, Kamala Harris headlined an Election Day event rally in Philadelphia on the same evening Joe Biden was in Pittsburgh. The Biden-Harris ticket flipped Pennsylvania from the GOP column four years after the state helped Trump defeat Hillary Clinton.

Last month, Harris introduced her running mate, Minnesota Gov. Tim Walz, at a raucous Philadelphia rally.

And tonight, she steps onto the presidential general election debate stage for the first time at the National Constitution Center.

Don't be surprised if she's back in Philly on the final night of campaigning before Election Day again this November.

Trump arrived in Philadelphia with an entourage

Along with family members, campaign officials and advisers, Donald Trump was joined on his plane by the far-right activist Laura Loomer, a controversial figure who has become one of his most loyal advocates on social media.

The 31-year-old Loomer has a long history of anti-Muslim and anti-immigrant remarks. She also has spread racist conspiracy theories, including the false notion that Harris isn't Black.

Top Trump surrogate wants difficult debate questions for Harris

North Dakota Gov. Doug Burgum says ABC has a responsibility to ask Harris tough questions tonight because she's done so few interviews.

Otherwise, he said, "I think America's going to be outraged."

Burgum is a top Trump surrogate who was on Trump's vice presidential shortlist.

Asked if there was a risk of Trump coming across too aggressively, Burgum argued the risk cuts "both ways." Harris, he noted, is a former prosecutor and well-practiced in memorizing attack lines.

"Depending on the tenor of how people are interacting with each other," he said, "either one of them could be viewed as being too aggressive."

Trump, he said, "is going to come out, he's going to make a decision, he's going to sort of read the room, if you will, and see what he's up against. Then I think he'll go from there."

Burgum said he wants "America to get to know the President Trump that I know, versus all these falsehoods that are told about him."

Trump arrives in Philadelphia

Donald Trump has arrived in Philadelphia ahead of the debate Tuesday night with Vice President Kamala Harris.

Harris arrived Monday afternoon after spending several days at a downtown Pittsburgh hotel preparing for the debate.

Harris has many tasks to balance

Kamala Harris has a lot to accomplish in her first presidential debate.

She's not an unknown, but she hasn't been president already like Donald Trump. Now she gets the biggest audience she's ever had to talk to voters still trying to decide whether they can see her behind the Resolute Desk.

But then there's her opponent, a deeply divisive figure who has been convicted of felonies, regularly criticizes U.S. institutions and promises an unapologetic conservative agenda if he returns to the White House.

And Harris, though not an incumbent, is a face of the Biden administration, which has notable legislative accomplishments but also has presided over an inflationary economy.

So, how much time will the vice president spend making her personal case? How much arguing against Trump? How much trying to take credit for Biden's wins while distancing herself from his liabilities?

How dark and dystopian will Trump go with Harris on stage?

At his rallies and other venues, Donald Trump paints an over-the-top image of an America under Kamala Harris.

"A crash like 1929 ... World War III ... the suburbs will be overrun with violent crime and savage, foreign gangs ... it will be crime, chaos and death all across our country."

His crowds believe it. But the audience Tuesday is the broader electorate. And Harris will be standing right there able to rebut him, either directly or simply by performing as a steady, mainstream figure that belies the caricature.

It's a risk Trump will have to weigh as he considers whether to employ his usual rhetoric.

The debate's set is smaller than it looks

It may look bigger on TV, but the set where the two candidates will be debating tonight is actually pretty small.

The candidates' podiums are positioned about 6-8 feet apart in a small, blue-lit amphitheater with no live audience in the room. That means there will be no rowdy applause, and no cheers or jeers.

The candidates will enter at the same time from opposite sides of the stage.

It remains to be seen whether they will shake hands.

Abortion rights could be an important topic in Harris-Trump debate

Democrats want Trump's role in overturning Roe v. Wade to be front-and-center in the debate, especially after President Joe Biden missed a chance to hammer Trump in their lone debate in June.

"Trump owns every single abortion ban in the country," the Democratic National Committee said in a statement Tuesday.

Harris brings up Trump's position on abortion in every campaign speech, reminding voters that Trump has bragged that his three Supreme Court nominees were instrumental in the 2022 Dobbs decision that overturned Roe after nearly a half-century of women having a constitutional right to terminate a pregnancy. Republican-run states across the country have since implemented near or total bans on surgical abortions.

Harris proved effective as an advocate on the issue ahead of the 2022 midterms, and Democrats relish the chance she will have as just the second female presidential nominee of a major U.S. party to confront Trump on the matter face-to-face.

After debate, allies to make arguments for candidates in the spin room

The official debate action takes place on the stage, but both Harris and Trump will have a large contingent of allies making arguments on their behalf in the spin room afterward.

Harris will have a number of Democrats whose names popped up as possible running mates for her, including Govs. Gavin Newsom (California), Roy Cooper (North Carolina), Josh Shapiro (Pennsylvania) and Michelle Lujan Grisham (New Mexico). There are also a handful of members of Congress: Sens. Tammy Duckworth, Chris Murphy and Laphonza Butler, as well as Reps. Jason Crow, Veronica Escobar, Robert Garcia and Ted Lieu. Mini Rimmaraju, CEO of Reproductive Freedom for All, retired Brig. Gen. Steve Anderson, and Khizr Khan, the father of a Muslim American soldier killed in Iraq who famously asked Trump if he had read the Constitution during an appearance at the 2016 Democratic National Convention.

In addition to Vance, his running mate, Trump will be represented by Republican National Committee Chairman Michael Whatley and his co-chair, Lara Trump, who is also Trump's daughter-in-law.

There will also be several Republicans whom he defeated during the primary campaign -- North Dakota Gov. Doug Burgum, Sen. Tim Scott of South Carolina and entrepreneur Vivek Ramaswamy -- as well as Robert F. Kennedy Jr., who shuttered his independent bid and endorsed Trump just weeks ago. There's also Tulsi Gabbard, a former House member from Hawaii who left the Democratic Party in 2022 and has backed Trump.

The former president will also be supported by other top surrogates like South Dakota Gov. Kristi Noem, Sens. Marco Rubio and Rick Scott of Florida, Sen. Tom Cotton of Arkansas, Florida Reps. Byron Donalds and Matt Gaetz and Rep. Mike Waltz of Texas.

Tonight's debate venue is rich with historical significance

It's the scene of tonight's debate, but the National Constitution Center has also played host to a number of other pivotal political moments.

The venue in the heart of Philadelphia is across from the Liberty Bell and Independence Hall, where the Founding Fathers debated and signed the U.S. Constitution and Declaration of Independence.

In 2008, it was the scene of then-Sen. Barack Obama's "A More Perfect Union" speech, largely credited as among the more memorable remarks of the campaign of the candidate who went on to become the first Black U.S. president.

That speech came also amid controversy around his longtime pastor, the Rev. Jeremiah Wright, whose anti-American rantings threatened Obama's presidential campaign.

Harris is the first Black woman to serve as vice president, as well as the first Black woman who is a major-party presidential nominee in the U.S.

The center has hosted presidential debates before, including a Democratic primary matchup between Obama and Hillary Clinton, and a town hall with GOP nominee Sen. John McCain, both also in 2008.

Biden says Harris seems 'cool and collected' ahead of the debate

President Joe Biden said he had a chance to chat with Vice President Kamala Harris ahead of Tuesday night's debate. He seems to think she's ready for her one-on-one with Donald Trump.

"She seemed calm, cool and collected," Biden said in an exchange with reporters.

Biden wouldn't reveal what advice he might have offered Harris.

The president is spending debate night in New York, where he said he planned to celebrate his granddaughter Finnegan's birthday and watch the debate.

Biden will start his Wednesday in New York to mark the anniversary of the Sept. 11 attacks on the U.S. He will also visit the Pentagon and Shanksville, Pennsylvania, memorials.

If debates are as much about style as substance, what will the candidates wear?

Former President Donald Trump seemingly has a uniform: navy suit, white dress shirt (pointed collar, no buttons) and a red necktie (always tied longer than the rules of men's fashion dictate).

Vice President Kamala Harris is most often seen in custom pantsuits ("powersuits" in women's fashion parlance) in solid colors but often with a contrasting blouse. Pearls are a go-to jewelry choice. And she likes American flag lapel pins of varying designs.

But there are plenty of potential surprises.

In 2016, Trump showed up for the first debate wearing a blue necktie, and Hillary Clinton donned a bright red suit. It was a reversal of the colors usually associated with each political party -- to the delight and consternation of social media. Trump also has worn a striped necktie for debates, including one matchup against President Joe Biden in 2020.

As vice president, Harris has worn a range of colors, including bright hues that go beyond what men in politics typically sport. She's also not afraid to wear serious heels -- and the candidates will be standing, shoes visible, in Philadelphia.

There have been occasions that might offer clues about her choice against Trump.

In the 2020 vice presidential debate, when the candidates were seated, Harris wore a navy suit and blouse. She added a flag lapel pin and contrasting white pearls. Harris repeated the choice of a navy suit in her Democratic nomination acceptance speech last month. But that time, she opted for what fashion experts refer to as a pussybow blouse with a subtle pinstripe.

Earlier this year, at what we now know was Biden's last State of the Union address, Harris also chose a dark suit, black by Alexander McQueen, with a cream Saint Laurent blouse. She mixed it up, though, for Biden's earlier speeches on Capitol Hill: a maroon suit and blouse, with black pearls in 2023; a chocolate-brown coat and matching dress by Sergio Hudson in 2022, with pearl earrings but no necklace; and, in 2021, a cream suit by Prabal Gurung.

What polling shows about Americans' debate expectations

Many Americans are keenly awaiting tonight's debate, according to recent polls.

A Quinnipiac poll of likely voters found that about 9 in 10 say they are "likely" to tune into the televised debate between Trump and Harris.

About half of U.S. adults (53%) said it was "very important" for there to be a televised debate between the two candidates, according to a Syracuse University/Ipsos Poll conducted in August. About two-thirds of Republicans (67%) called it "very important" compared to about half of Democrats and Independents.

The pressure may be a little higher on Harris. Americans are slightly more likely to expect Harris to "win" the debate over Trump, according to an ABC News/Ipsos poll. About 2 in 10 either anticipate a tie or say neither will win.

But the stakes are high for both: National polls conducted after Biden ended his campaign show a close race between the nominees. Polls conducted in key swing states after Biden withdrew from the race -- including Pennsylvania, Michigan, Wisconsin, North Carolina, Nevada and Georgia -- show a similarly close contest.

Trump's and Harris' advantages going into the presidential debate

Polling shows that Vice President Kamala Harris enters the presidential debate as the candidate who Americans are more likely to perceive as honest, committed to democracy and as someone who cares about people liking them, according to an August AP-NORC poll.

But former President Donald Trump has an edge over her when it comes to Americans thinking he's being better positioned to handle the issues of economy and immigration.

Harris has more of an advantage over Trump when it comes to handling issues related to race and racial inequality, abortion policy and health care. Americans may also expect her to appear as a composed candidate -- about half (47%) of Americans say the phrase "disciplined" better describes her over Trump (28%).

And although Trump has spent the campaign championing himself as a strong leader who is capable of handling tough crises facing the country, the AP-NORC poll shows Americans overall do not give him an advantage over Harris on those traits.

Trump's strength currently lies in the fact that Americans are slightly more likely to trust Trump over Harris when it comes to handling the economy or immigration. Independents are about twice as likely to trust Trump over Harris on economic issues.

Harris' running mate says debate will show she is the most qualified for the job

Democratic vice presidential nominee Tim Walz says Kamala Harris is the most qualified person for the job, and Tuesday's debate will show it.

Walz was speaking at a fundraiser in Las Vegas ahead of the 9 p.m. ET debate between Vice President Kamala Harris and Republican Donald Trump.

He said Trump might be a "showman" with a lot of experience debating -- "no one in modern times has done more of these. The good news is that this is his seventh debate, and we know exactly what to expect."

A look at false and misleading claims as Trump and Harris meet for their first debate

Former President Donald Trump and Vice President Kamala Harris will meet face-to-face for the first time in a highly-anticipated debate Tuesday night. The two presidential candidates describe the state of the country in starkly different terms. Trump often paints a dark picture centered around issues such as immigration and high inflation, while Harris focuses on optimism for the future, promising that "we're not going back."

The first debate of the 2024 election in June -- at which President Joe Biden's disastrous performance ultimately forced him from the race -- featured multiple false and misleading claims from both candidates and it's likely that Tuesday's match-up will include much of the same.

? Read more about claims made by the candidates