Republican J.D. Vance and Democrat Tim Walz will meet Tuesday in the lone vice presidential debate of the 2024 election, bringing together undercards who have spent two months going after each other and the opposing nominees who top the major-party tickets.

The matchup, hosted by CBS News in New York, might not carry the same stakes as the Sept. 10 debate between former President Donald Trump and Vice President Kamala Harris. But it offers their top lieutenants a fresh opportunity to introduce themselves, vouch for their bosses and fulfill a time-honored role of a running mate: attack dog. It will involve the biggest television and online audience either No. 2 will see before Election Day.