NEW YORK, Oct 1, 2024 (BSS/AFP) - US vice presidential contenders J.D. Vance and Tim Walz face off in what could be an unusually important undercard debate Tuesday as they compete for decisive votes in America's heartland just weeks before the election.

The showdown between Walz, the Democratic Minnesota governor chosen by Kamala Harris, and Vance, the Republican senator from Ohio who is Donald Trump's running mate, is likely to be the last of the 2024 campaign.

Trump has refused a second debate with Harris, meaning this could be the final chance to see the two tickets go head to head.

Vance, 40, and Walz, 60, each claim to be the true voice of the crucial Midwestern swing states -- including Michigan and Wisconsin -- that could decide an election that remains on a knife-edge with five weeks to go.

History suggests vice presidential debates rarely move the dial much. But in an election campaign that has seen Harris step in for US President Joe Biden unprecedentedly late in the game, Tuesday's contest may have added significance.

The race has seen Vance and Trump use increasingly divisive rhetoric and even falsely accuse immigrants of eating people's pets -- meaning that the debate is almost guaranteed to make for fiery television.

"It will whet a lot of people's appetites for November 5," Thomas Whalen, an associate professor of social sciences at Boston University, told AFP.

The CBS clash comes in the aftermath of Helene, an enormous storm which has brought misery to thousands, left at least 130 people dead across six states, and taxed the ability of federal and local authorities to respond.

Trump visited a hard-hit area in Georgia on Monday and claimed "the federal government is not being responsive." 

Harris canceled campaign events, returned to Washington and met with emergency management teams to discuss the response. Her message to those affected: "Our nation is with you."

The devastation, and how to address such disasters, is likely to come up during the debate.

- 'High drama' -

Walz and Vance were each picked by their bosses to reach out to voters in the Midwestern battlegrounds where, thanks to the country's idiosyncratic electoral college system, a few thousand votes could determine who wins the White House race.

Both are military veterans with strong blue-collar credentials. Vance authored the Rust Belt memoir "Hillbilly Elegy" while Walz boasts a folksy persona as a former teacher and football coach.

The similarities end there.

The combative Vance shares Trump's penchant for courting controversy, whether by smearing Democrats as "childless cat ladies" or by boosting false claims that Haitians living in an Ohio town ate residents' pets.

His goal will be to overcome polls that initially had him as one of the least popular VP nominees in history, after a series of previous comments on women and abortion were unearthed.

"Vance has to be careful, because I think a trap has been laid for him," said Whalen.
Democrats also pulled off pre-debate hijinks Monday, projecting messages on Trump Tower, just six blocks from the debate locale at CBS Broadcast Center in New York, including a quote from Vance referring to Trump as "an idiot."

The cheery Walz will be seeking to introduce himself to a public that barely knows him, after Harris's swift rise to replace Biden as the Democratic nominee.

He became a hit with Democrats for branding Vance and Trump "weird" and for his progressive politics -- but that will be a target for Vance as he and Trump seek to paint Walz and Harris as "Marxists."

Vance "is going up against a moron, a total moron," Trump said in an interview Monday on Fox Nation.

Televised debates have already proved their ability to shock this year, with Biden forced to drop his reelection bid after a disastrous performance against Trump in June brought long-simmering concerns about his age to the fore.

Whalen said few vice presidential debates have "had any appreciable difference" in the past, but Tuesday's clash could produce "high drama" for viewers who love political theater.

The Vance-Walz debate could feature extra spice given that their microphones will be live throughout, allowing them to cut in on their rivals.