The football coach and the “Yale law guy” go head-to-head in New York City on Tuesday night, as two midwesterners with very different styles and vastly diverging messages slug it out over the future of the US.

Tim Walz, the Democratic governor of Minnesota, faces the Republican senator from Ohio, JD Vance, in a vice-presidential debate that promises to be unusually significant in this white-hot election year. They will joust for 90 minutes under the moderation of CBS News as they seek to give their respective running mates – Kamala Harris and Donald Trump – a leg up to the White House.

Walz has been prepping for the debate in Minneapolis with the US transportation secretary, Pete Buttigieg, masquerading as Vance. (Buttigieg may have been suffering deja vu – he posed as Mike Pence during Kamala Harris’s prep sessions ahead of the 2020 VP debate.)

Vance has been holding mock debates with the Republican whip in the US House, Tom Emmer, standing in as Walz. Emmer is a fellow Minnesotan, so has the benefit of having studied Walz up close.

The two running mates bring contrasting strengths to the gladiatorial ring. Vance is an experienced debater who will relish confrontation under the glare of the TV lights.

“Look, he’s a Yale law guy,” Walz has said about his opponent. “He’ll come well prepared.”

Walz by contrast will be able to lean on skills learned in the school classroom. Walz spent 17 years as a public school teacher, so he knows how to think on his feet – and deal with a disruptive kid.

“I expect to see a very heated debate,” Robby Mook, Hillary Clinton’s 2016 presidential campaign manager, told CBS News.

One of the big questions of the night is likely to be whether Vance can redeem himself after a troubled start to his candidacy. Will he be able to get past all the “weirdness”, as Walz has framed it, and bring consistency to the messaging of an often chaotic Trump campaign?

From awkward encounters with doughnut shop workers, to the ongoing furor around his “childless cat ladies” remark, Vance has been the subject of online mockery that has at times appeared to engulf him. He also seems to be stuck on the same culture war issues that consume Trump.

“Vance does not seem to have drawn additional voters to the Trump ticket, as the controversies he gets into are exactly the same as those the former president gets into,” said Barry Burden, a political scientist at the University of Wisconsin, Madison.

Most egregiously, Vance has doubled down on the false and racist narrative that Haitian immigrants are eating family pets in Springfield, Ohio, despite categorical denials from local authorities. He recently confessed to CNN that he was willing to “create stories” if it meant that he attracted media attention.

Such comments have sunk Vance underwater in the opinion of the voting public – his unfavorability rating is 11 points higher than his favorable, according to FiveThirtyEight.

Walz by contrast is basking in the glow of a positive four-point gap between his favorability ratings, which poses him with a completely different set of challenges on debate night. He will need to parry Vance’s attempts to frame him as the misinformation candidate based on misrepresentations Walz made about his military record, defuse his rivals claims that he is dangerously liberal, and refuse to be knocked off track.

“Walz just needs to get in and out of the debate without causing trouble for his ticket,” Burden said.

John Conway, director of strategy for Republican Voters Against Trump, said that Walz was best advised to follow Harris’s playbook. He organised focus groups the day after Harris’s debate with Trump, involving voters from five battleground states who backed Trump in 2016 but switched to Biden in 2020.

The focus group attendees were enthusiastic about Harris’s dual approach to the debate – attack Trump for his lies and felony convictions, but also lay out a positive plan for the future of the country. “That’s the blueprint Walz must follow,” Conway said, “attack when appropriate but also be substantive on the issues.”

There have been several memorable made-for-TV moments from the VP debates since the first in 1976 between senators Bob Dole and Walter Mondale. Most celebrated is the 1988 incident when the Democrat Lloyd Bentsen chastised George H Bush’s running mate, Dan Quayle, for comparing himself to John F Kennedy.

“Senator, I served with Jack Kennedy. I knew Jack Kennedy. Jack Kennedy was a friend of mine. Senator, you’re no Jack Kennedy.”

“That was really uncalled for, senator,” Quayle wailed.

More recently, John McCain’s running mate, Sarah Palin, ribbed Joe Biden, the Democratic VP candidate running with Barack Obama, in 2008, by telling him: “Aw, say it ain’t so, Joe.”

Those were neat soundbites that entered the lexicons. But it is notable that neither Bentsen nor Palin were rewarded where it matters – at the ballot box.

In fact, vice-presidential debates have tended to be underwhelming in terms of the lasting imprint they have left on US elections. Larry Sabato, professor of politics at the University of Virginia, pointed out that even after the dynamic presidential debate between Harris and Trump earlier this month, which was watched by 67 million TV viewers and which Harris was widely judged to have won, the race remains essentially neck-and-neck in the critical battleground states.

Sabato said that given the lack of consequences from the debate at the top of the ticket, he expected Tuesday’s vice-presidential tussle to be equally inconclusive. “I don’t expect the vice-presidential debate to make any impact,” he said.

Yet this is no ordinary election. Joe Biden’s departure and the sudden elevation of Harris, together with Trump refusing to participate in a second debate with her, has raised the stakes.

Tuesday’s spectacle will probably be the final debate before election day on 5 November. “This is really the last main national moment in the campaign, so I do think it is important,” Mook said.

Apart from the economy, immigration and foreign wars, which are certain to be addressed during the debate, a more amorphous struggle is likely to play out on stage: who will own the mantle of “authentic midwesterner”? Will it be Nebraska-born Walz, or the bestselling author of Hillbilly Elegy, Ohio’s Vance.

The rivalry goes beyond mere aesthetics or regional loyalties. It resonates heavily in those states where the election could be decided – the three so-called “blue wall” states of Wisconsin, Michigan and Pennsylvania.

“I don’t know if the word ‘midwestern’ will be used in the debate, but feelings about the midwest will come through,” Burden said.

The candidates offer a diametrically opposed vision of the heartlands. Walz’s midwest is folksy and homely, a world where neighbors look after each other, where football coaches double up as local heroes (Walz coached the sport at Mankato West high school from 1997), and where joy fills the air.

Vance’s is a much darker picture of drug addiction, broken families and the threat of immigration. His is the midwest of Trump’s “American carnage” dystopia.

Two utterly contrasting visions. Two tough and determined candidates. Gentlemen, shall we begin?