Justin Trudeau's decision to boot Liberal senators from his caucus as part of a larger plan to restore Senate independence is bold, opportunistic... and puzzling.
It's puzzling because Thomas Mulcair's New Democrats had proposed the same measure last October, but only the Bloc Québécois's four members supported the motion. Every Liberal voted it down because, as MP Stéphane Dion said at the time, the NDP motion was both "ridiculous" and unconstitutional.
It's unclear what has happened in the last few months to change Mr. Trudeau's mind, although critics have suggested it might be related to the pending audit of Senate expenses, which could set off a new round of political recrimination if the audit shows Liberal senators have been feeding at the trough.
Mr. Trudeau's sudden move to separate Liberal senators from Liberal MPs is a good idea because it promotes the idea that the Senate and the House are unique bodies that should operate independently.
It could pressure Prime Minister Stephen Harper to consider the same measure -- actually he also already decided that the leader of the Conservative party in the Senate will no longer automatically be a member of cabinet -- but there is no need to act immediately.
That's because the real debate on the future of the Senate shouldn't occur until after the Supreme Court of Canada has ruled on a series of questions referred to it by the government.
The court is considering whether Parliament can unilaterally impose term limits and set up a process for "consultative elections" of Senate nominees. The Harper government has also asked the court to consider what would be required to abolish the Senate.
Legal opinions vary on all these questions, with some lawyers saying nothing can change without the approval of seven provinces representing 50 per cent of the population.
Outright abolition might require the unanimous consent of the provinces, according to some legal sources.
Once the court has ruled on these matters, it will be easier to frame the debate about the future of the Senate.
Mr. Harper has made it clear he's not interested in a divisive constitutional conference, but if the court rules that is the only way to make any changes, then Parliament and the country will be left to consider the kind of improvements proposed by Mr. Mulcair and now by Mr. Trudeau.
If the audit discovers widespread abuse has been occurring with expense accounts and housing allowances, however, public outrage could easily tilt the debate in favour of fundamental change, or even abolition. In that case, a constitutional conference might be the least painful and most productive of all the options.