For a supposed party of the common man, the NDP sure has a curious way of picking its spots.

Of all the issues the only consistently left-of-centre federal party might want to focus on, one would think private health care or urban poverty or access to post-secondary education would top the list. But last week, a prominent New Democrat MP decided the issue that really matters to his party's support base - is who owns the federal government's office buildings.

Responding to Public Works Minister Scott Brison's suggestion that certain buildings could be sold to the private sector and then leased back, Winnipeg MP Pat Martin was apoplectic. "If he does this, we will flip out," he pronounced. "It will be a declaration of war as far as we are concerned."

Now, there are plenty of reasons for critics to take issue with Mr. Brison's proposal. They might choose to dismiss his protestations that this isn't simply a cash grab, and lament efforts to mortgage the future for a short-term fix. Or worry that, with the government having little option of going elsewhere, private property owners would wind up inflating rents to untenable levels. But it's hard to imagine that a single person living in the real world - i.e. outside the government culture that pervades Ottawa -- would consider this one of the defining issues of our time.

Granted, it might be a bit much to take Mr. Martin literally, since that would suggest that he doesn't believe the Liberals had already waged war on NDP principles in their first 11 years in government. One of Parliament's more colourful orators, he's not above using a bit of hyperbole to get his point across. But still, he clearly thought this was an issue worthy of the strongest and most outraged reaction he could muster. And that speaks to a broader problem that continually hampers the NDP's efforts to take itself to the next level.

No Canadian party is more introspective. Whereas the Liberals or Conservatives worry about how to put forward a platform that will strike a chord with mainstream Canadians, New Democrats spend a great deal of time on pet issues that matter to their core members, but are relevant only to a very limited segment of the population. With a membership made up mostly of committed activists (unionists, social workers, environmentalists, the anti-globalization crowd, etc.), leaders must spend as much time trying to convince the faithful that they're committed to core NDP principles as trying to win over converts.

The result is a party that is immensely true to itself, but also immensely irrelevant to people who might otherwise be inclined to vote for it - working parents struggling to get by, urbanites who see the need for increased social spending, students mired in debt and facing an uncertain future, and so on.

Under the leadership of Alexa McDonough, the NDP responding to its devastating 2000 election showing by lurching further from mainstream interests than ever before. Attempting to ride the pre-9/11 anti-globalization wave, New Democrat MPs tried to reassert their relevance by turning up at WTO protests. The results weren't pretty: Youthful protesters had no idea what to make of middle-aged folks professing their eagerness to fight the power, and everyone else saw the party embracing an agenda that they couldn't identify with.

Since taking over for Ms. McDonough, Jack Layton has gone a considerable distance toward shifting the NDP back toward policy areas that genuinely concern the broader public. But the party still has a tendency to get bogged down with pet causes that alienate potential supporters.

Mr. Martin's war on private buildings is one example, albeit an extreme one. But consider that perhaps the most memorable aspect of the NDP's election platform was its pledge to build thousands of wind turbines, and that Mr. Layton appears to be more passionate about opposing missile defence than about tackling serious domestic challenges.

The NDP's environmental commitments are perfectly noble, and a left-wing party has every reason to oppose missile defence. But to lower-income voters trying to get by in Atlantic Canada or recent immigrants struggling to establish themselves in Toronto or Vancouver, these aren't the issues that are top of mind. They don't particularly care if the NDP is being true to its principles; they just want to know if it can help make their communities more liveable, their families more secure and their children's future a little brighter.

Mr. Layton is shrewd enough to know that there's a considerable space to the Liberals' left that's there for the taking. But it remains to be seen if he knows how to get the NDP there - and if all those shrill voices within it will let him.