OTTAWA — There is an interesting line in one of the new campaign ads from the Conservatives.

The ad runs down the NDP and Liberals and then a female actor says, “Stephen Harper isn’t perfect but when it comes to the economy, we can depend on him.”

For a party that has so steadfastly refused to admit any of its shortcomings over nearly a decade in power this is a remarkable admission.

But it may also be a politically canny one that could pay off at the ballot box on October 19.

Ontario voters may remember a television ad the Ontario Liberals used in the 2011 provincial election. The polls, at the time, showed a tight two-way race between Dalton McGuinty’s Liberals and Tim Hudak’s Progressive Conservatives. But the polls also showed that McGuinty was a drag on his party’s numbers, that he had become personally unpopular with voters.

So early on in the campaign, the Ontario Liberals rolled out a TV ad in which McGuinty, alone against a white background, smiled sheepishly at the camera and confessed: “Well, the polls tell us I’m not the most popular guy in the country. I accept that.”

But then he said, “Doing what’s right is not always doing what’s popular.”

It was a heckuva gamble by the Liberal war room but it paid off.

They ran a sharp campaign. Their opponent, Hudak, made some mistakes. And McGuinty won his third consecutive term, something no Liberal in Ontario had done for more than 100 years. In fact, he came one seat shy of winning a majority.

Harper, too, is trying to pull off a rare historic feat and win four consecutive elections, something only done twice in our history and then it was done by a couple of guys named Macdonald and Laurier.

And Harper’s trying to do it using a bit of the same basic pitch that McGuinty used to great effect in the 2011 Ontario election, namely concede that you haven’t done everything as perfectly as you would have wished — Harper said as much in that leaders’ debate Thursday — then convince the electorate that you got the big important things right while warning voters that taking a gamble on the other guys just isn’t worth the risk.

But what are those imperfections to which the Conservative campaign has confessed? I’ve got three.

The first, perhaps oddly enough, is the energy file. As NDP Leader Thomas Mulcair noted in that Thursday debate, not a single new kilometre of pipeline has been built while Harper was prime minister. Our Western oil remains largely landlocked.

Harper, of course, is quite right to say it’s up to private sector companies to propose, finance and build these things. But if Harper wins, perhaps he could take a cue from Northwest Territories Premier Bob McLeod who has quietly forged considerable consensus among government, First Nations communities and environmental activists to create some winning conditions for resource development in the Western Arctic.

The second imperfection is defence spending. You won’t hear Mulcair or Liberal Leader Justin Trudeau pushing Harper to boost spending on our military but our allies are taking note that we’re not pulling our weight here.

We’re now spending just 1.5% of GDP on defence. That’s 8th worst among our NATO allies and well below the commitment we made to NATO to spend 2% of GDP on the military. Our navy is in desperate shape. Our search-and-rescue capability is as bare bones as it gets.

And finally, there’s the issue of Harper and the Conservatives failing to play nice with others. Harper personally can be warm, generous, and compassionate. That was most obvious the day after the terrorist attack on Parliament Hill. But the standard operating procedure for his party is to use an often vicious scorched-earth policy against any critic or opposition.

Harper is never going to be touchy-feely everyday in public — and no one wants that — but a Conservative government that takes a bit more of an adult, intelligent approach to criticism would be welcome.

No, he’s not perfect. But with less than 30 days to go in this campaign, Stephen Harper — warts and all — has an excellent chance to set the same record as Sir John and Sir Wilfrid.