By "longer term trends" I just mean people not making projections off the latest horse race figures. Those are very tentative anywhere- and people who make projections off them are usually in the category of using them to dress up wishes.

And it is a truism they can change again. But take note that what you observed as a [longer running] upward trend for the Liberals in Quebec has shown to be an extremely short blip ["My name in Michael Ignatieff."] in a long dismal run. Ditto for your prediction the Bloc is now in a slode further from its good  old days- rather than apparently in a plateau that is showing a lot of stability through all the changes [at least in relation to competing with the Liberals, if perhaps not the Cons].