Karl Nerenberg offers one comparative look at how the NDP and the Libs are positioned for the next few years after this weekend's conventions which saw Tom Mulcair resoundingly confirmed as the NDP's leader and Justin Trudeau anointed as the Libs'. But I'll take a bit of time to discuss the wider political scene - and how the most important choice over the next few years may still lie in the hands of Stephen Harper and his party.
While media coverage of polls inevitably tends toward proclaiming a horse race, the trend since Trudeau has instead pointed toward another possibility: for the foreseeable future, we figure to be in a true three-party system, where relatively small shifts can create plausible scenarios in which each of the NDP, Libs and Cons has a path to power. And the range of possible outcomes is only heightened by the respective positions of the NDP and the Libs - who can be seen as exemplifying the fable of the tortoise and the hare.
For the NDP, the next steps look mostly to involve continued progress along the party's existing trajectory. While the 2011 Quebec breakthrough may have provided a bit more public attention and a stronger base in Parliament than expected, the path ahead still means implementing the strategy first developed when Jack Layton won the leadership over a decade ago - including consolidating the NDP's hold over progressive policy positions (as Frank Graves points out), further outreach to groups who haven't been sufficiently included before, and slowly but surely building Mulcair's reputation as a strong and steady leader defined by a commitment to social democratic causes ignored by the other two official parties.
For the Libs, on the other hand, the only goal for the moment is to catch lightning in a bottle. As Andrew Coyne notes, the entire party is now focused entirely on Justin Trudeau alone, which creates both obvious opportunities and significant dangers. It's possible that the Libs may be able to harness an immediate outpouring of attention to jump-start the fund-raising, volunteer and activist bases needed to support a government-in-waiting. But the Libs are effectively starting from scratch yet again in trying to assemble those pieces - and if Trudeau loses his political celebrity status before they're in place, then that may well be the end of the party as a viable political force.
Which leads us to the most interesting factor to watch over the next few years.
Stephen Harper's time as the Cons' leader has been defined primarily by two goals: to incrementally spread small-c conservative values around the political scene to the extent possible, and to kill off the Liberals as a viable political force. And until 2011, there wasn't any need to choose between those two goals, as any action which supported one tended to contribute to the other.
But with Trudeau conspicuously trying to position himself as a centre-right leader while the NDP has emerged as a serious contender for government in its own right, the two goals may now be mutually incompatible.
The "spread conservative values" goal might well be best achieved (at least in the sense of trying to secure another majority in 2015) through a strategy of opposition whack-a-mole: launching concerted attacks on whichever opposition party manages to reach relative parity with the Cons at any given time, and easing off to allow either party to rebuild strength if it's in danger of falling out of the picture entirely.
Of course, that line of attack isn't without its risks either: in particular, if the two opposition parties are both allowed to push their support into the high twenties or beyond, a minority scenario could easily materialize which Harper wouldn't likely survive. And moreover, a three-party system featuring the Libs as a significant option obviously falls short of the goal of performing a victory dance on the Libs' corpse.
That leaves the other possibility. It's often been mooted that Harper's long-term goal is a system akin to that which has existed in B.C. for the past few decades - with a right-wing coalition which can be assembled (under various party banners) to win a majority of elections in the long run, and a left-wing counterweight strong enough to contend in most elections but facing a small, persistent structural disadvantage.
And Harper will have some significant influence in determining whether that dynamic materializes. If he simply decides to attack Trudeau early, often and with even less regard than usual for the Cons' immediate popularity, he may well be able to push the Libs over the edge. But in so doing, he'd almost certainly improve the NDP's chances of emerging on top in 2015. (And it might well have other unintended side effects - such as reinforcing so many negative perceptions as to push his own party into third place if Trudeau's popularity holds up.)
So these may be the choices facing Harper: between an Ontario-style three-party system which often requires triangulation and compromise or a B.C.-style winner-take-all ideological slugfest; between Justin Trudeau having a better chance to come to power pushing centre-right policies or Tom Mulcair receiving a greater opportunity to implement centre-left ones; between short-term power in 2015 and a long-term party alignment which he may see as more consistent with his agenda.
I have my own suspicions as to what will prove the be the overriding force in the Cons' decision-making. And I see the first wave of attacks on Trudeau supporting the theory - though I'll have more to say about those later on.
[Update: Corrected fable. Fun update to be able to offer.]