Presidential nominees Hillary Clinton and Donald Trump are set to meet Monday night for the first time on the debate stage, and with months of a topsy-turvy general election campaign behind them, no one is quite sure what to expect.

But local politicos and election observers agree on one thing, at least: It's definitely going to be must-see TV.

That's due in large part to Republican presidential nominee Donald Trump, whose campaign has at times offended and titillated voters. Grove City College professor Michael Coulter said Trump's aggressive, off-the-cuff style and penchant for creating controversy has stoked interest in the debate like few candidates before him have managed.

“Everybody's paying much more attention to this one because Trump is unpredictable as a candidate,” said Coulter. “Everybody wants to know what he could say or do on stage, because he could say a couple things we've never seen before.”

What should viewers expect to see and hear Monday night as Trump faces off with Clinton? And what might the outcome of the contest be?

That's a topic of much more debate — with supporters of each candidate claiming Monday will be a definitive moment for their campaigns. For Trump supporters like Larry Thompson, the vice chairman of the Butler County Republican Committee, Monday is a chance for Trump to capitalize on momentum his campaign has drawn from a series of poor news cycles for Clinton following her near-collapse at a 9-11 memorial event in New York City, and the subsequent revelation that she had failed to immediately disclose a pneumonia diagnosis.

“I think the country is surging toward him (Trump),” Thompson said. “I think he can help himself very much if he stays on point, is not rattled at all, and doesn't go off on a tangent.”

Thompson said he expects Clinton to try and do just that — rattle the real estate mogul and draw him into outrageous or combative statements. Instead, Thompson wants Trump to speak more on his “America first” policy positions, as well as how he would change a foreign policy crafted by Clinton and President Barack Obama that he believes has failed and cost America its standing on the world stage.

“I want to hear him say (how) he's going to promote Americanism and American exceptionalism here and abroad,” said Thompson. “I think people are going to be looking for more from Donald Trump on leadership.”

For Jack Beiler, the treasurer of the Butler County Democratic Committee, Monday is Clinton's chance to define herself as the only candidate with the experience and poise necessary to be commander-in-chief.

“I think Hillary will stick to the issues,” Beiler said. “I hope she is very presidential, and I think she will be. I don't think she'll get down (and) try to compete with Trump's nasty comments.”

Beiler wants the candidates to address the issue of violence across the country, specifically the riots that have broken out in response to police shootings, as well as persistent instability throughout the Middle East following America's invasion of Iraq and Afghanistan after the 9-11 attacks.

For a politico like Phil English, an Erie resident and GOP delegate who served in the U.S. House of Representative for six years, the debate is a risk-reward calculation for both candidates. Given their unpopularity — Trump is the most unpopular presidential candidate in modern history, and Clinton is a close second — and the fact that expectations for Clinton's performance are higher, English believes Trump has more opportunities to make gains Monday night.

“I think it's going to be hard to shake the dynamic that these are two unpopular and polarizing candidates,” English said. “I think the risk is higher for Mrs. Clinton, because she goes in with higher expectations, and this is a real opportunity for Donald Trump. I think he performs well as a presenter, and his communication skills have been consistently underestimated by his adversaries.”

But will any of it ultimately matter in the long run?

Political observers — Coulter and Brian Harward, a political-science professor at Allegheny College — say that people looking for a big polling bump or momentum shift for either candidate are probably going to be disappointed.

In general, both said, televised debates between presidential candidates haven't proven to be game-changers when it comes to election outcomes or even polling results in the wake of the contest. Since 1960, Harward said, candidates might see at best a two-point shift in polling numbers following a particularly one-sided contest or a memorable debate gaff. Even in those cases, he said, it's difficult to point to a candidate's debate performance as the direct cause.

“It's hard to disentangle what the effects of the debates really are,” Harward said. “There were some shifts, but it's not clear that debates were even responsible for those shifts.”

Coulter agreed, noting debates between Al Gore and George Bush in 2001 and Mitt Romney and Barack Obama in 2012 as examples.

In 2001, a poor debate showing by Gore — he was perceived as rude for interrupting Bush multiple times — dogged him throughout the rest of the campaign. In 2012 Romney's “binder full of women” comment became a clarion call for Democrats painting him as tone-deaf.

Coulter said moments like those actually show us the value of presidential debates. They can produce unscripted moments that are otherwise rare on the campaign trail.

“It puts both candidates together and makes them respond; that's the sort of symbolic importance of this,” Coulter said. “The political importance is ... the impression the candidate can give, or the statement that can stick with you (as a candidate).”

Both candidates likely understand that, Harward said, and accordingly have decisions to make. For Trump, Harward said, a “lid” on his support means he has to decide whether he can, or should, try to broaden his appeal. One way to do that is to focus on policy and leadership, which are things that resonate with moderate Republicans, whom Trump has struggled to reach.

“I think to become moderately successful in this debate he needs to give a nod toward decency, and policy,” Harward said. “He's going to have his moment, so if he's able to muster some up, it'll be a great move for him.”

For Clinton, Coulter said, the calculus is more complicated. Does she try to get under Trump's skin, or does she focus on policy and looking more presidential than the real estate mogul?

The decision is complicated, Coulter said, because while Clinton has broader appeal than Trump does, his supporters are far more enthusiastic than hers.

“She's not going to convince committed Trump supporters to vote for her,” Coulter said. “She's got to solidify some of her supporters. Trump has some incredibly enthusiastic supporters, but there appears to be a ceiling. Her support seems a little broader, but not as strong.”