He may end up with a road block instead.
The top court will hand down Friday its opinion on how the disgraced, scandal-plagued upper house can be reformed or abolished.
"The Supreme Court's opinion will provide a legal instruction manual on how we can proceed with Senate reform," Pierre Poilievre, the minister responsible for democratic reform, said in an email.
But the court may well conclude that the only possible route involves constitutional amendments approved by at least seven provinces — a road so fraught with potholes, so potentially dangerous for the unity of the country, that it amounts to a political dead end.
Wrangling over the Meech Lake and Charlottetown constitutional accords in the early 1990s nearly tore the country apart and Harper has said he has no interest in plunging back into that quagmire.
Hence, his best hope for reforming the Senate lies in the top court accepting his position that imposing a nine-year term limit on senators and creating a process for "consultative elections" of Senate nominees are mere housekeeping measures that can be unilaterally carried out by the federal government.
The chances of that do not appear good.
The eight justices who presided over a three-day hearing last November appeared skeptical about the federal arguments.
They seemed somewhat more sympathetic to the argument advanced by the vast majority of provinces: that the reforms would change the fundamental character of the Senate as an independent, unelected, regionally equal chamber of sober second thought — the creation of which was part of the "bargain" struck at Confederation.
Consequently, the provinces maintained, the reforms should not proceed without substantial provincial consent. They argued that a constitutional amendment would be required, supported by seven provinces representing 50 per cent of the country's population (the so-called 7-50 amending formula).
The eight justices who heard the case took the rare step of appointing two "friends of the court" — lawyers Daniel Jutras and John Hunter — to give them some impartial advice.
On term limits, both Jutras and Hunter sided with the majority of provinces.
But the two diverged on the consultative election issue. Jutras agreed with the provinces that the 7-50 formula should apply, while Hunter maintained the federal government could proceed unilaterally — so long as it was clear the election of Senate nominees was non-binding and the prime minister remained free to appoint whomever he pleases.
The prime minister currently can consult friends, family, party activists or even a ouija board about whom to appoint to the Senate, Hunter noted.
"The only thing he can't do it consult the electorate, and that's a rather remarkable proposition," he told the court.
That said, Hunter argued that the two Senate election bills the Harper government has proposed thus far went too far in fettering the prime minister's discretion, essentially requiring him to appoint only the winners of consultative elections.
If the court is looking for some middle ground, it could adopt Hunter's position on the election of senators.
And it could conceivably agree that the federal government can unilaterally impose a term limit, provided the term is long enough that it doesn't appreciably change the status quo. Senators currently serve for an average of about 15 years before reaching mandatory retirement at age 75.
Harper has threatened to abolish the Senate altogether if his plans for reform are stymied. But he has not explained how he'd go about that without reopening the constitutional can of worms he's vowed to keep closed.
In its submission, the federal government acknowledged a constitutional amendment would be required to get rid of the Senate. It maintained the 7-50 amending formula would be sufficient, but the majority of provinces — as well as Jutras and Hunter — argued that abolition would require an even higher hurdle: unanimous provincial consent.
Whatever the court concludes, its advice is bound to have repercussions for the three main political parties, potentially scuppering Harper's reform agenda and making NDP Leader Tom Mulcair's dream of abolishing the chamber more elusive.
Liberal Leader Justin Trudeau, for his part, has slagged both Harper and Mulcair for championing solutions to the Senate that he considers unachievable, given the constitutional hurdles.
Trudeau has promised to stay focused on practical reforms that can be accomplished without reopening the Constitution, such as his surprise decision last winter to kick senators out of the Liberal caucus.