The off-year state race could be a sign of Democrats' strength or weakness ahead of the 2022 midterm congressional elections, as well as a test of the political strength of the president and his Republican predecessor.
Democrats hope next year to keep control of the U.S. House of Representatives, in which they have a slim majority, and the Senate, in which there is a 50-50 split, while Republicans hope to take over leadership of both chambers.
Biden traveled the short distance from Washington to a park in Arlington, Virginia, for the event for McAuliffe, a long-term fixture in Democratic politics who is running for a second term as Virginia governor in November's election.
"Terry and I share a lot in common. I ran against Donald Trump and so is Terry," Biden said. "I whipped Donald Trump in Virginia and so will Terry."
Biden kicked off his remarks by tweaking some conservatives who have recently begun recommending vaccination against COVID-19.
"Some of our very conservative friends have had an altar call. They've seen the Lord," he quipped.