On central questions

A few notes on the Calgary Centre by-election we'll see in the relatively near future as a result of Lee Richardson's departure from Ottawa...

First, it would of course be a major shock to see any party other than the Cons marshal a win in Calgary. It's been over 40 years since a party without a conservative label won a seat in the city - and while the usual low turnout in a by-election might increase the range of possible outcomes, it doesn't figure to make up for a 40-point gap all at once.

But the race for an anticipated second place (if not an upset victory) still promises to be an important one.

As I've pointed out, Calgary was one of only two major urban areas where the Libs managed to run ahead of the NDP in 2011. But the gap was a fairly small one - and the margin between second and third in Calgary Centre was only three points despite the Libs making the seat a main Calgary target.

What's more, that was at a time when the national polling gap between the NDP and the Libs was 12 points rather than the current 15. So the starting point for the by-election may be something close to a dead heat in support. And that could turn the by-election into a litmus test as to which party's overall message resonates best in the most favourable possible Calgary terrain - not to mention an opportunity for the NDP to cement its status as the clear alternative to the Cons across the country.

Further complicating matters, the Greens ran a respectable campaign in 2008 to fall just short of second place (only to drop off in 2011 as the party focused on its single-seat strategy). Which surely creates some potential upside for them in putting up as much of a fight as they can - but also means their possible Etobicoke Centre option of staying on the sidelines doesn't look to be on the table.

Of course, there's also an obvious question as to which parties will have spare resources to use in a riding where there's an extremely limited prospect of getting elected. But beyond the value of organizing generally, each party has reason to view the by-election as a crucial signal as to who can challenge the Cons on their own turf - and the outcome might thus be more significant than we'd normally expect from an early-term by-election.