In the lead up to the next federal election, PM Steven Harper has made Senate reform the central plank in his overall thrust for the democratization of Canada's Parliamentary institutions and electoral system. Senate reform and economic and fiscal austerity, he believes, will get his beleaguered Conservative a second majority. The strategy is a big gamble. Yet, the Prime Minister has no choice because of the continued rise in popularity of Justin Trudeau's Liberal Party. He is also well aware of the growing dissension within the rank and file of the Conservative Party's three constituencies - social conservatives, fiscal conservatives, and democratic reformers. He has virtually written off Québécois nationalist conservatives but would like the NDP to hold the majority of seats in Quebec.Pierre Polièvre, Minister of State for Democratic Reform, is only nominally in charge of Harper's senate reform agenda. The ongoing Senate scandal, involving Conservative Senators Wallin, Duffy and Brazeau, has clearly shown that it is Harper who is calling all the shots. He is doing all the tactical and strategic planning. Senate reform is now a veritable three ring circus entailing Harper's juggling of interconnected legal, constitutional and political dimensions.Prime Minister Harper is so angry and so determined to suspend all three Senators for two years without pay because they have become a huge liability to his longer-term strategy of achieving an elected Senate -- or its outright abolition. Over the summer, Harper decided to go on the attack. He is now exploiting the Senate scandal by having his leader in the Senate, Senator Claude  Carignan, introduce a motion calling for the suspension of Duffy, Wallin, and Brazeau for two years without pay. As expected, the three senators took the bait and obliged Harper by fighting back rather than accepting their pre-ordained fate. Next, Harper will whip his 60 senators into passing the suspension motion before he meets with his rank and file at the Conservative Party Convention in Calgary to great applause.However, Harper has far less control over the legal and constitutional dimensions of his Senate reform agenda. On 24 October 2013, the Quebec Court of Appeal published its decision in the Reference re Bill C-7 Concerning the Reform of the Senate case. The Quebec Court of Appeal, drawing upon legal scholarship and relevant case law including Re: Authority of Parliament in relation to the Upper House, [1980] 1 S.C.R. 54 and Reference re the Secession of Quebec, [1998] 2 S.C.R. 217, concluded that “… Bill C-7, if it had been adopted, would have been unconstitutional without the agreement of the majority of the provinces pursuant to subsection 38(1) of the Constitution Act, 1982, since its true nature was to amend the method of selection of senators and the powers of the Senate without having respected the applicable amending procedure. In reality, Bill C-7 attempted to circumvent that procedure.”In sum, Harper's Bill C-7, which died on the Order paper thanks to his prorogation, was blatantly unconstitutional.Sensing that the Quebec Court of Appeal would render a problematic negative decision and impatient with the stalling tactics of the critics of Bill C-7 in the House and the Senate, in February 2013 the Prime Minister launched his Reference to the Supreme Court of Canada on Senate Reform. His reference entails six questions.  Can the Parliament of Canada:Establish unilaterally fixed terms for Senators? Enact legislation that enables Ottawa to consult the population of each province and territory as set out in Bill C-20, the Senate Appointment Consultations Act? Establish a framework enabling the provinces/territories to carry out elections for potential nominees to be appointed to the Senate? Repeal the provisions of the Constitution Act, 1867 regarding property qualifications for Senators?Questions 5 and 6 pertain to the amendment method required to abolish the Senate. Can it be done under section 38 of the Constitution Act, 1982 requiring the consent of 7 provinces comprising 50% of the population? Or, must abolition be achieved under section 41 of the Constitution Act, 1982 requiring unanimous consent of all ten provinces?The decision of Quebec's Court of Appeal and the input of provincial governments and other intervenors critical of the Harper government's defence of Bills C-7 and C-20 provisions will have a substantial impact on the deliberations of the SCC judges and their ultimate legal decision and political advice in Harper's complex reference case. There will be two dimensions to the SCC's ruling.The first dimension will entail the Court's legal decisions that will affirm what constitutional requirements and amending procedures must be followed for various amendments to the Senate. The second aspect of the Court's ruling will entail advice on how the Harper government should proceed with Senate reform based on established constitutional principals and political conventions as were spelt out in the SCC's landmark 1998 Reference re the Secession of Quebec decision. These included federalism, democracy, constitutionalism and the rule of law, and respect for Canada's minority communities.Harper and his constitutional advisors are well aware of the nature and scope of the Supreme Court's forthcoming legal and political rulings concerning his reference case.  Using the Senate scandal, for which he is largely responsible, as his trampoline, Harper has launched his political campaign to convince a majority of Canadians that the status quo of the Senate is no longer acceptable.In the next federal election we can expect Stephen Harper to offer Canadians two options: an elected and reformed Senate controlled by the provinces/territories or the abolition of the Senate.  He will have to resort to a national referendum to win the support of a majority of Canadians for either option.Why? Harper will need this democratic legitimacy to compel the approval of at least 7 provinces comprising 50% of the population for some amendments. If, according to the SCC's ruling, Harper requires the unanimous support of all provinces for other amendments to the Senate or the outright abolition of the Senate, which he is highly unlikely to get, he may well have to return to the Supreme Court for a further ruling and advice on how to proceed. The SCC may rule that something less than unanimity but more than 7 provinces is required for abolition.It took Prime Minister Trudeau 15 years to obtain the long overdue Constitution Act, 1982, with its highly popular Charter of Rights and Freedoms. This accomplishment is central to Trudeau's legacy.  Will Harper succeed with Senate reform where Brian Mulroney failed so miserably in 1992 with his ill-fated Charlottetown Consensus Report? Perhaps. But it most certainly will take Prime Minister Harper another majority government in 2015 and lots of luck if he wants to leave a similar constitutional legacy, one pertaining to an elected Senate of Canada or its outright abolition.Michael Behiels is a professor of Canadian Political and Constitutional History and former Research Chair in the Department of History at the University of Ottawa. He has written and lectured extensively on Canadian political affairs, with a particular focus on political, ideological and constitutional development pertaining to the Canadian federal system and Quebec's role within the federation. His latest co-edited book is The State in Transition: Challenges for Canadian Federalism (Invenire Books, 2011).