As the Liberal and Conservative war rooms keep burying each others' leaders in muck, it raises two questions.

1. Will voters start migrating over to the NDP, Greens, and People's Party of Canada in larger numbers?

2. Or will voters still be more likely cast ballots for the party most likely to defeat the party they hate the most?

In 2015, the largest number of voters decided that Justin Trudeau was the best vehicle to get rid of Stephen Harper's Conservatives.

Trudeau won his majority and promised "sunny ways" on election night.

In this election, however, the stakes seem so much higher, given the increasing gravity of the climate crisis. And two frontrunners, Trudeau and Conservative Leader Andrew Scheer, don't appear up to the job of tackling it, given their political records.

It's also becoming increasingly clear that both Trudeau and Scheer are sneaky.

Say what you will about the NDP's Jagmeet Singh, the Greens' Elizabeth May, or the PPC's Max Bernier, all three are beacons of transparency in comparison to the smirkers-in-chief of the Liberal and Conservative parties.

Going into the campaign, Trudeau's shortcomings were apparent—he twice violated the Conflict of Interest Act. And he spouted platitudes about the climate while doing everything he could to ram through some pipeline and liquefied natural gas projects.

Plus, Trudeau and his staff tried to bully his attorney general into getting a deal for a Quebec-based corporation to avoid corruption charges.

Trudeau's problems were compounded by the blackface and brownface scandal.

He never revealed the existence of this political skeleton to his party until it blew up in the middle of an election campaign—and he's been apologizing ever since.

Scheer won his party's leadership race in 2017 with the help of thousands of anti-abortionists. Yet he refused to reveal his position on this issue during the French-language leaders' debate.

Only on the following day did Scheer admit that he's "pro-life"—while claiming he won't reopen this issue if elected.

Keep in mind that Scheer has allowed a multitude of anti-abortionists to run as Conservative candidates.

And we don't know if he'll try to stack the superior courts across the country with anti-abortion judges and so-called "originalists" if he becomes prime minister.

Scheer also misled the public and his own party that he was a licensed insurance broker. And he didn't divulge that he held dual citizenship even after raising questions about the dual citizenship of a former governor general.

No wonder he's being accused of hypocrisy just as he levels the same accusation against Trudeau for using two campaign planes while professing to be an environmentalist.

https://twitter.com/CPC_HQ/status/1179864953034960896

It's already looking like support for the Conservatives is going to crash in Quebec in the wake of the French-language debate.

The Bloc Québécois appears ready to become the preferred choice of most of those Quebeckers outside Montreal who dislike the Trudeau Liberals.

If the public in the rest of Canada gets the sense that Scheer can't win, this could create problems for Liberal candidates.

That's because it would become less risky for those who dislike the Conservatives to abandon the Liberals and vote NDP or Green.

The NDP's Singh, in particular, has acquitted himself with a great deal of dignity in this campaign.

Many believe Singh won the Maclean's English-language debate, which Trudeau skipped. Singh also fared far better than Scheer in the French-language debate.

In addition, Singh came across exceptionally well while being on the firing line with undecided voters on CBC News.

May can also peel votes away from the Liberals in some ridings because of Trudeau's dismal record on the climate. That was apparent earlier this year in the Nanaimo-Ladysmith by-election, when support for the Liberals plummeted.

There's no questioning May's understanding of the magnitude of the climate crisis, nor her commitment to embrace the recommendations of scientists in tackling it.

Her only serious stumbles in the campaign came in connection with the recruitment of former Quebec NDP MP Pierre Nantel as a candidate and not realizing that a former New Democrat's defection to the Greens in New Brunswick wasn't quite what it seemed. 

Trudeau needs the public to think that the Conservatives have a chance. It's the best reason for many progressives to vote Liberal.

This is why the Monday (October 7) English-language leaders' debate is so critical.

If Scheer comes across as not ready for prime time—or simply as a U.S.-style socially conservative trickster—then voters may start to write off his chances.

More right-wing voters could migrate to the People's Party of Canada's blunt-speaking leader, Max Bernier.

It doesn't take that many to drive down Conservative support to where Scheer can't win a majority.

Then if progressives feel confident that Scheer won't form a government, they could feel a little freer to vote for their preferred candidate rather than against Scheer.

In many cases, that preferred candidate would not be Liberal—it would be a Green or a New Democrat.

In this campaign, Singh and May haven't given them any monumental reasons not to support them.

That's mainly because they haven't been as sneaky and disingenuous as the two front runners.