WASHINGTON — Tim Walz and JD Vance will meet for their first and possibly only vice presidential debate Tuesday night, in what could be the last debate for both campaigns to argue their case before the election.

The debate in New York hosted by CBS News will give Vance, a Republican freshman senator from Ohio, and Walz, a two-term Democratic governor of Minnesota, the chance to introduce themselves, make the case for their running mates, and go on the attack against the opposing ticket.

Tuesday’s 9 p.m. matchup could have an outsized impact.

Polls have shown Vice President Kamala Harris and former President Donald Trump locked in a close contest, giving added weight to anything that can sway voters on the margins, including the impression left by the vice presidential candidates.

It also might be the last debate of the campaign, with the teams of Harris and Trump failing to agree on another meeting.

The role of a presidential running mate is typically to serve as an attack dog for the person at the top of the ticket, arguing against the opposing presidential candidate and their proxy on stage.

Both Vance and Walz have embraced that role.

Vance’s occasionally confrontational news interviews and appearances on the campaign trail have underscored why Trump picked him for the Republican ticket despite his past biting criticisms of the former president, including once suggesting that Trump would be “America’s Hitler.”

Walz, meanwhile, catapulted onto Harris’ campaign by branding Trump and Republicans as “ just weird,” creating an attack line for Democrats seeking to argue Republicans are disconnected from the American people.

A new AP-NORC poll found that Walz is better liked than Vance, potentially giving the Republican an added challenge.

After a Harris-Trump debate in which Republicans complained about the ABC News moderators fact-checking Trump, Tuesday’s debate will not feature any corrections from the hosts. CBS News said the onus for pointing out misstatements will be on the candidates, with moderators “facilitating those opportunities.”

Ahead of the debate, allies of both men were lowering expectations that their candidate will have a decisive performance.