WASHINGTON – Tim Walz and JD Vance might have the chance to reshape the political landscape Tuesday in their first and only debate.

Vice presidential picks have traditionally taken on the role of political attack dog, laying into opponents so that their running mate can appear above the political fray. That’s generally been less true since former President Donald Trump scrambled political norms.

But Walz, the Democratic governor of Minnesota, made it to national prominence by labeling rival Republicans “weird.” Vance, the Republican junior senator from Ohio, has torn into Vice President Kamala Harris’ party on immigration, notably by spreading a false story about Haitian immigrants in his home state that Trump then cited during his own debate with Harris.

Here’s a look at past vice presidential debates — and the larger role of the office Walz and Vance are both seeking.

What is the vice president’s job?

The vice president presides over the Senate and is empowered to break ties, as Harris has done a record 33 times. She exceeded the previous high mark last year, which had held since John C. Calhoun was vice president from 1825 to 1832. The officeholder also presides ceremonially in Congress over the certification of electoral results, which Vice President Mike Pence did even after a mob of Trump supporters stormed the U.S. Capitol on Jan. 6, 2021, in a bid to halt the process and transition of power, with some chanting, “Hang Mike Pence!”

But the vice president’s main job is to be ready to take over if something happens to the president. Nine have done so following a president’s death or departure from office — the last being Gerald Ford, who became president when Richard Nixon resigned in 1974.

The Constitution’s 25th Amendment, ratified in 1967, spelled out the succession rules, stating that the vice president becomes president “in case of the removal of the president from office or of his death or resignation.” It also allowed the president and Congress to nominate and approve a new vice president if that office is vacated.

Vice presidential historian Joel K. Goldstein said two recent assassination attempts against Trump raise “the saliency of succession.” But he added that many voters view vice presidential nominees as appendages of the candidates who selected them, not necessarily as potential future presidents themselves.

“People do look at somebody as, are they ready to be a heartbeat away?” Goldstein said. “But it is also a question of how good a decision maker is the person who chose them.”

Memorable vice presidential debates featured Palin, Bentsen — and Harris

In 1992, Adm. James Stockdale, running mate of third-party candidate Ross Perot, was going for breezy but seemed befuddled when he opened the debate by saying, “Who am I? Why am I here?” His later response to a question, “I didn’t have my hearing aid turned up,” only reinforced that perception.