Kennedy, an anti-vaccine activist and environmentalist who ran for president as an independent before endorsing Trump, on Monday posted a video on social media that he filmed outside the U.S. Department of Agriculture headquarters in Washington.

"Corporate interests have hijacked the USDA dietary guidelines to make natural unprocessed foods merely an afterthought. That's one reason why 70% of the American diet now consists of ultraprocessed food. We're going to change that," Kennedy said, before listing off a series of policy ideas that would seem to run counter to much of what Trump's Agriculture Department did in his first administration.

"When Donald Trump gets me inside the building I'm standing outside of right now, it won't be this way anymore. American agriculture will come roaring back, and so will American health."

The Trump campaign has said in a statement that formal discussions of who would serve in a second Trump administration are "premature." But the former president himself has said at recent rallies that RFK Jr. is someone who could help his administration if he wins.

"We will make America healthy again. You know who's going to do that? RFK Jr. He's got some good ideas," Trump said at a rally in Reading, Pennsylvania.

The prospect of Kennedy's influencing a wide array of federal policy has raised alarm bells among advocates of sound science. Public health experts have pointed to Kennedy's pivotal role in spreading false information and sowing fear around the world about vaccines, as well as conspiracy theories about technology like 5G. While there are rare instances when people have severe reactions to vaccines, the billions of doses administered globally provide real-world evidence that they are safe. The World Health Organization says vaccines prevent as many as 5 million deaths each year.

Trump, who is locked in a tight contest for the presidency with Democrat Kamala Harris, embraced Kennedy's endorsement in August after the scion of the famous Democratic political family suspended his third-party bid. He had built an unusually strong base for an independent candidate, propelled by anti-establishment voters and vaccine skeptics who have followed his anti-vaccine work since the COVID-19 pandemic.

Although public polls didn't provide a clear indication that he is having an outsized impact on support for either major-party candidate, there was some evidence that Kennedy's staying in the race would hurt Trump more than Harris. In an AP-NORC survey conducted in July, about half of Republicans had a favorable view of Kennedy, compared to about 3 in 10 Democrats and a similar share of independents.

When endorsing Trump, Kennedy suggested that Trump had offered him a job if the former president returns to the White House, but neither he nor Trump offered details. Before the endorsement, the Kennedy campaign told the HBO show "Last Week Tonight" in August that the two had discussed "the possibility of a Cabinet position -- HHS," referring to the Department of Health and Human Services, which oversees the Centers for Disease Control and Prevention, the Food and Drug Administration and the National Institutes of Health, among other agencies.

Kennedy has made a series of videos this month in which he says that he plans to exercise his influence over a wide range of policies if Trump wins.

The U.S. Agriculture Department, which Kennedy discussed Monday, is the primary agency in charge of support for farmers, animal and plant health and the safety of meat, poultry and eggs. It oversees federal nutrition programs that provide food to low-income people, pregnant women and young children and school lunches.

Kennedy's background as an environmental lawyer isn't likely to be broadly popular in agriculture, however. He has challenged the widespread use of herbicides like Roundup and the large commercial farms and animal feeding operations that dominate the industry because they are the most efficient way to raise crops and animals. Bayer, which makes the Roundup weedkiller, has been hit with tens of thousands of lawsuits alleging it causes cancer, an accusation the company denies.

"If I were Trump, I'd try to get him to shut up as quick as possible. You really think RFK would sell very well in farm country?" said John Hansen, the longtime president of the Nebraska Farmers Union.

Many of the policies pursued by Sonny Perdue, the agriculture secretary during Trump's first term, favored the massive farms and livestock operations that Kennedy rails against.

On Oct. 1, Kennedy posted a video filmed in front of the Environmental Protection Agency, where he said he planned to work on issues of health and the environment. Four days later, he posted that he was partnering with Trump "to transform our nation's food, fitness, air, water, soil and medicine."

"Our big priority will be to clean up the public health agencies like CDC, NIH, FDA and the U.S. Department of Agriculture. Those agencies have become sock puppets for the industries that they're supposed to regulate," Kennedy said.

Last week, he targeted the Food and Drug Administration in a video filmed outside the U.S. Capitol.

"I want to get on the inside of FDA to make America healthy again," he said, ending the video with the line: "Get Donald Trump in the White House in November, and me over at FDA."

A Kennedy spokesperson did not return messages seeking comment Tuesday.

Brian Hughes, senior adviser to the Trump campaign, said it was too early to say who would serve in a Trump administration, but that a Trump-Vance transition leadership group was preparing for "what comes after the election."

Mike Haag, a Trump supporter who farms about 2,000 acres and raises about 6,000 pigs a year near the small town of Emington, Illinois, said he doesn't think Kennedy would be a good pick for the Agriculture Department, but he's not going to worry about it too much at this stage.

"I can't imagine it would be good, but until Trump actually says he's going to do that, I probably wouldn't actually let it hold much water either," Haag said.

Kennedy's anti-vaccine nonprofit group, Children's Health Defense, currently has a lawsuit pending against a number of news organizations, among them The Associated Press, accusing them of violating antitrust laws by taking action to identify misinformation, including about COVID-19 and COVID-19 vaccines. Kennedy took leave from the group when he announced his run for president but is listed as one of its attorneys in the lawsuit.