When New Democrats chose Jack Layton as their leader in 2003, they were looking for a slicker, more populist, more dynamic party. Enough with all the earnestness, they were saying: It's time to be players on the national stage.

This week, Mr. Layton gave them exactly what they asked for, striking political gold that neither his predecessor nor his former leadership rivals would have had the street-smarts to find. But for all the giddiness surrounding his deal with the Liberals, the leader and his followers would do well to recall the bitter disappointment of last June.

Of all the parties, the NDP was left the most bitter on election night. The Liberals would have preferred to keep their majority, but they could take solace in holding on to power at all. The Conservatives were disappointed not to form government, but could take pride in boosting their seat count and ending the Liberals' stranglehold on power. The Bloc Quebecois had nothing to complain about at all.

The NDP, on the other hand, could find little encouragement in picking up a few extra seats. With Mr. Layton's campaign team having predicted right up until June 28 that it would take as many as 40 ridings, the final count of 19 bordered on embarrassing. And cruelly, the party spent most of election night believing it would hold the balance of power in the new minority parliament - only to realize, once most Canadians had gone to bed, that it fell one seat short.

New Democrats still complain bitterly that they were victims of Liberal scare tactics. And they're right -- voters in ridings where the Conservatives ran a distant third were convinced to transfer their votes from the NDP to the Grits to keep Stephen Harper out of the Prime Minister's office. But the bottom line is that if voters are really sold on you, their support isn't so tentative that they flee at the first opportunity.

Mr. Layton is a natural salesman - especially now that he's gone through an image makeover to give him a little more gravitas, which means he no longer seems better suited to selling used cars than public policy. But the biggest part of selling yourself and your product is knowing your market.

On that front, the NDP will need to do much better than it did in 2004.

If Mr. Layton's party is going to make major inroads, it will be in cities. More than anywhere else, that's where left-of-centre voters who traditionally opt for the Liberals find themselves in a conundrum. They can't in good conscience support a crumbling governing party that, even aside from Adscam, seems to have no semblance of a plan to run the country. And they can't be expected to vote for a Conservative party that favours a brand of government they're uncomfortable with, and that spends far more time trying to woo rural, suburban and small-town voters than urban dwellers.

The numbers from last year's vote prove urban ridings are there for the NDP's taking. In at least 13 constituencies - five in Greater Vancouver, four in Toronto and two each in Halifax and Hamilton - the party is within striking distance of the incumbent, all but two of whom are Liberals. If the bottom drops out on the Grits and the Conservatives again fail to connect with city voters, there could be even more.

But those voters aren't just going to fall into Mr. Layton's lap. He has to win them over - not with airy promises that keep the NDP's contingent of environmentalists, anti-war activists and unionists happy, but by becoming the country's staunchest advocate for issues that actually matter to urbanites.

Before he took office, Paul Martin seemed to have the "new deal for cities" ground covered. But after helping to make that one of the country's defining issues, the Prime Minister effectively abandoned it, offering little more than token gestures. As a result, the urban renewal agenda is now there for someone to seize.

A longtime Toronto councillor and former head of the Federation of Canadian Municipalities, Mr. Layton couldn't possibly be better positioned to do so. But in the last campaign, he spent as much time talking about windmills as he did about putting more money into cities.

From now until election day, Mr. Layton should hardly step outside cities. And he should remember that when they get to the voting booth, urban voters won't much care what he did to get post-secondary funding in this year's budget. They'll want to know he's capable of representing them in the way the other parties aren't. Only if he convinces them of that will he avoid a repeat of last year's disappointment.