Tim Hudak has spent Ontario's election campaign offering himself quite convincingly as the rare politician willing to level with voters about difficult decisions he thinks are needed, even if some of them may not want to hear it.

The Progressive Conservative Leader's efforts to present himself as a straight shooter, however, are in the midst of taking a big hit from the laughable math error on which his pitch has been premised – and, even more so, from the way Mr. Hudak has reacted to that error being exposed.

There is, in fairness, no good response to the revelation that his promise of a million new jobs revolves partly around counting many of the hypothetical jobs eight times. Having spent millions of dollars advertising that pledge, Mr. Hudak would risk turning himself into a punchline if he somberly announced he needed a do-over.

Story continues below advertisement

His best option might be to say that the "million jobs" figure is aspirational – that it's not worth obsessing over the minutiae of precisely how many each new policy will create, but that any leader who doesn't think they could achieve such employment gains over two terms as premier shouldn't be seeking that office. But during a visit Thursday to The Globe and Mail's editorial board, he declined to make that argument even when invited to do so.

Instead, Mr. Hudak continued to stand behind numbers that a legion of economists has discredited. Economists are known for contradicting each other, he insisted, overlooking that in this case they weren't disputing projections but pointing out that he was counting each year a person works in a new job beyond the first year as an additional new job. When that didn't work, the PC Leader – himself a trained economist – more or less pretended not to understand the question.

Mr. Hudak is hardly the first politician to present faulty numbers, and only the most gullible would take such economic projections as gospel. He is running against a Liberal Leader whose government's plan to eliminate the deficit by 2017-18 could generously be described as short on specifics, and an NDP Leader whose platform's costing appears to have been done on the back of a napkin. But one would like to think if those leaders learned their figures were predicated on basic methodological errors, they would acknowledge it and move on. And neither of them is otherwise spending the campaign purporting not to gloss over hard truths.

That Mr. Hudak hasn't adjusted owes partly to his characteristic reluctance to abandon talking points once he has settled on them. In the last provincial campaign, he continued to insist the Liberals were proposing to reward employers for hiring "foreign workers" long past the point he had to know that wasn't accurate. So he's not inclined to move from a less inflammatory claim in which he has more invested.

He is also likely banking on the inability of even an army of economists to sway his base. The Tories' campaign strategy is less about winning over new supporters than mobilizing existing ones to vote, and whereas perceived weakness could demotivate them, an army of fact-checking economists probably won't.

Still, there is a swath of moderately right-leaning voters swinging between his party and the Liberals, and another (mostly in the province's southwest) trying to choose between the Tories and the NDP. These are people motivated both by a desire for change and a mistrust of the opposition leader likeliest to bring it. And the "million jobs" mess could badly undermine Mr. Hudak's efforts to address the latter, especially if his opponents are able to use it against him in next week's leaders' debate.

If Thursday's editorial-board meeting was any indication, Mr. Hudak could spend most of that debate passionately making the case for his vision of a smaller, more efficient government, only to undermine himself when talk turns to the pledge after which he named his platform.