The former vice president’s first acts as a nonelected official for the first time in decades could be a sign of what comes next.

At age 40, a relative newcomer who made his name on the campaign trail for his fierce attacks on Democrats is first in the line of succession for president.

Before Joseph R. Biden Jr. was sworn in 2021, Donald J. Trump held the record for the country’s oldest commander in chief. He reclaimed the record on Monday.

The vice president presided over Congress on Monday as it counted the Electoral College votes finalizing her defeat by Donald J. Trump.

Walter F. Mondale died in 2021, but he left behind the eulogy he planned to deliver at former President Jimmy Carter’s funeral.