It's hard to imagine, but even in a tight electoral race where the front-runners have seesawed for the lead in polls over the last four weeks, tonight's debate — what promises to be a dramatic highpoint of the Ontario election campaign — might have little bearing either way.

It will be Liberal Leader Kathleen Wynne's first foray into the oratorical big leagues, while Progressive Conservative chief Tim Hudak and the NDP's Andrea Horwath get their second chance to score points in an election debate.

But even if one of the party leaders emerges as a consensus winner, there's no guarantee that will translate into votes. Horwath was seen as having the momentum in a snap post-debate poll last time around. It wasn't enough to propel her party past third place in the legislature, however.

Leaders debate live

Follow tonight's leaders debate live on CBCnews.ca, CBC TV, CBC News Network and CBC Radio One (Ontario), starting at 6:30 p.m. ET. Click here for more details.

Join in our live blog starting at 6 p.m. at cbc.ca/ontariovotes — and then, after the debate, use Vote Compass to rate the leaders' performance at cbc.ca/votecompass

"Debates don't change opinions; they really solidify opinions and then motivate or demotivate people. That's what truly matters," said Rob Silver, a partner at public-affairs agency Crestview Strategy and a former adviser to Liberal ex-premier Dalton McGuinty.

"There aren't a lot of undecided people who tune in to leaders' debates."

Tonight's contest will see the three major-party leaders square off at the CBC studios in Toronto. Here are five things to watch for:

1. Tim Hudak's no-act act

While his politics take a page from former U.S. president Ronald Reagan — slashing the size of government and sabre-rattling at labour unions — Hudak and his team say he won't be channelling the Gipper's vocation in tonight's debate.

"Nothing exciting, not a great actor, straight up," is how the PC leader describes the image he's hoping to cultivate.

His campaign communications director, Will Stewart, says Hudak is going to "look at the camera and talk straight to Ontarians. We're not going to be flashy," Stewart said. No mock debates today or even yesterday, Stewart related. The challenge for the Tory leader will be to connect with voters and to appear simultaneously decent and personable but authoritative, all the while upbraiding the Liberals.  

2. Kathleen Wynne's balancing game

The predicament for an incumbent like Wynne, heading a party that's been in power for 10½ years, is to appear fresh but offer stability at the same time.

"She has tried to own that with the pension plan, with the budget and other measures they've brought forward," Silver said. "If she can present herself as the premier with an ambitious agenda for Ontario, then she will be happy."

Wynne will also find herself besieged. The NDP has squandered few opportunities to try to pin the C-word — corruption, as in gas plants and Ornge and eHealth Ontario — on the Liberals. And while Hudak's campaign has had a more positive tone this time around, the PC leader will need to go on the offensive at some point if he's to persuade voters to ditch the government.

3. Andrea Horwath's preparation

To hear Horwath's team tell it, the NDP leader has turned preparation for tonight's debate into a science. Horwath has been practising on a mock set that re-creates the CBC-TV studio chosen as the setting for the real contest, according to a source close to the campaign. Stand-ins played her opponents. The campaign team has even adjusted the height of the lecterns and the placement of TV cameras to mimic the actual stage, the source said.

NDP strategists are counting on the debate's equal-time format to level the playing field between Horwath and front-runners Wynne and Hudak.

4. On message

Debates are rarely the place for an Earth-shattering policy announcement that will shake up the campaign. They're more about soliciting voters' trust. "Because the issues are always changing and what may be important may change tomorrow, you're almost picking someone based on their values. You pick the person based on the beliefs that what they represent is more important than the actual issue of the day," said Howard Brown, president of media relations firm Brown & Cohen.

That favours candidates reciting, and repeating, a small number of key points from their platforms rather than regurgitating a mess of policies. "You pick three or four issues. You have three or four different ways of saying the same thing," said Allan Bonner, a communications consultant and specialist in issues management. "You deploy those issues or that attack or that statement three times during the hour."

5. Spin cycle

"As important as the debate is the coverage," Silver says. "What happens on stage is really interesting, but most people form their opinions based on the coverage and the reactions in the 24 hours after the debates."

The Tories are already in spin mode, with the debate still hours away. Communications director Stewart said he expects a wild "swing for the fence" tactic from Liberal campaign co-manager and chief strategist David Herle, who coached former prime minister Paul Martin before the 2006 federal election debate. (Martin famously declared during that exchange that if his government was kept in power, he would scrap the notwithstanding clause from the Charter of Rights and Freedoms.)

The post-debate spin can help decide whether a winning debate performance translates into votes.


Tonight's debate 

The leaders' debate, hosted by journalist Steve Paikin, begins at 6:30 p.m. ET and runs until 8 p.m. ET. 

  • Watch it live on CBC News Network and CBC Television. 
  • Listen live on CBC Radio One (Ontario only). 
  • Watch livestreaming video online and take part in our live blog at cbc.ca/ontariovotes
  • Get a debate wrap up and analysis on CBC Television News at 11 and online at cbc.ca/ontariovotes.
  • Rate the leaders performance after the debate at cbc.ca/votecompass