Past leaders' debates haven't moved the dial much, and that's bad news for the NDP

In tonight's leaders' debate, the NDP's Ryan Meili is going to have to do something none of his predecessors have managed in the last few provincial elections use it to move public opinion and shift the momentum before the Oct. 26 vote.

The New Democrats need to see the numbers change over this last stage of the campaign. Two polls published over the last few days put Scott Moe's Saskatchewan Party ahead by between 19 and 22 percentage points among decided voters.

That's a huge margin to overcome in just a couple weeks.

The CBC's Saskatchewan Poll Tracker estimates that the Saskatchewan Party is on track to win between 39 and 49 seats, well above the 31-seat threshold needed for a majority government. In fact, the Sask. Party could win all the seats it needs for a majority outside of the two major cities, where the race is more competitive.

That shows the kind of challenge Meili faces in this debate. His party is running about even with the Sask. Party in Regina, but it is trailing by a wider margin in Saskatoon and is completely out of contention in the rest of southern Saskatchewan.

For the result of this election to be put into doubt, Meili needs to do something to close the gap in Saskatoon, take a decisive lead in Regina and gain enough support in the rest of the province to put some of the seats in places like Moose Jaw and Prince Albert into play.

Shifting the polls by 20 points is a big demand for any leader in any province. It's especially daunting in Saskatchewan.

Debates didn't help NDP challengers in 2011, 2016

Debates in the last three provincial elections have not moved the dial by any significant degree.

In 2016, the Saskatchewan Party was leading by an average of about 23 points over the NDP in pre-debate polling. Post-debate, Brad Wall boosted his party's edge over Cam Broten and the NDP to 29 points as the Sask. Party picked up about three or four points and the NDP slipped about two.

While a six-point swing is nothing to sneeze at, it went against Broten. To make the race competitive, Broten needed a swing at least three times that size and in his favour.

There weren't any early campaign polls published in 2011 but, compared to pre-campaign polling, Wall was able to boost his lead over Dwain Lingenfelter and the NDP to about 35 points after the debate from 32 pointsasmall swing, again to the incumbent's advantage.

There was also little movement in public support in 2007 between post-debate and pre-campaign polling. In the spring of that year, Wall's Saskatchewan Party was ahead of Lorne Calvert's governing NDP by about 18 points. By the end of the campaign, the lead was virtually unchanged, though the election day results showed a somewhat smaller 14-point gap.

Both rookies, but Moe begins with the edge over Meili

One common thread between the last three elections was, of course, Wall. In 2011 and 2016, when the debates apparently improved his party's fortunes, he was facing off against rookie NDP leaders. The NDP has another rookie leader this time, but so does the Saskatchewan Party in Moe.

That doesn't necessarily make it a level playing field. Polling by Research Co. suggests that Moe has an advantage going into the debate, as more Saskatchewan voters start the night with a positive view of him than they do of Meili. According to the poll, 45 per cent approve of Meili, compared to 65 per cent for Moe.

Research Co. also found that more people say their view of Moe has improved since the start of the campaign than those who say it has worsened. The opposite is the case for Meili.

That's a big obstacle for Meili to overcome, especially since the NDP needs a historically big swing in support to put itself in contention to win this election. If history repeats itself, this debate is unlikely to do the trick.