FILE - In this Oct. 15, 2019, file photo, Democratic presidential candidate former Vice President Joe Biden, left, and then-candidate Sen. Elizabeth Warren, D-Mass., arrive to participate in a Democratic presidential primary debate at Otterbein University in Westerville, Ohio. Biden’s search for a running mate is entering a second round of vetting for a dwindling list of potential vice presidential nominees, with several black women in strong contention. (AP Photo/John Minchillo, File)

FILE - In this June 2, 2020, file photo, Democratic presidential candidate former Vice President Joe Biden speaks in Philadelphia. Biden’s search for a running mate is entering a second round of vetting for a dwindling list of potential vice presidential nominees, with several black women in strong contention. (AP Photo/Matt Rourke, File)

In this June 11, 2020, photo, Democratic presidential candidate former Vice President Joe Biden speaks during a roundtable on economic reopening with community members in Philadelphia. Biden’s search for a running mate is entering a second round of vetting for a dwindling list of potential vice presidential nominees, with several black women in strong contention. (AP Photo/Matt Slocum)

FILE - In this July 31, 2019, file photo, then-Democratic presidential candidate Sen. Kamala Harris, D-Calif., listens as Democratic presidential candidate former Vice President Joe Biden speaks during a Democratic presidential primary debate at the Fox Theatre in Detroit. Biden’s search for a running mate is entering a second round of vetting for a dwindling list of potential vice presidential nominees, with several black women in strong contention. (AP Photo/Paul Sancya, File)

FILE - In this Jan. 16, 2020 file photo, Sen. Kamala Harris, D-Calif., talks to reporters about the impeachment trial of President Donald Trump on charges of abuse of power and obstruction of Congress, at the Capitol in Washington. Biden’s search for a running mate is entering a second round of vetting for a dwindling list of potential vice presidential nominees, with several black women in strong contention. (AP Photo/Matt Rourke, File)

FILE - In this Sept. 12, 2019, file photo, from left, Democratic presidential candidate former Vice President Joe Biden, watches as then-candidates Sen. Elizabeth Warren, D-Mass., and Sen. Kamala Harris, D-Calif., shake hands after a Democratic presidential primary debate hosted by ABC at Texas Southern University in Houston. Biden’s search for a running mate is entering a second round of vetting for a dwindling list of potential vice presidential nominees, with several black women in strong contention. (AP Photo/David J. Phillip, File)

FILE - In this Feb. 19, 2020, file photo, former national security adviser Susan Rice takes part in a discussion on global leadership at Vanderbilt University in Nashville, Tenn. Democratic presidential candidate former Vice President Joe Biden’s search for a running mate is entering a second round of vetting for a dwindling list of potential vice presidential nominees, with several black women in strong contention. (AP Photo/Mark Humphrey, File)

FILE - In this Dec. 11, 2019, file photo, Rep. Val Demings, D-Fla., gives her opening statement during a House Judiciary Committee markup of the articles of impeachment against President Donald Trump on Capitol Hill in Washington. Democratic presidential candidate former Vice President Joe Biden’s search for a running mate is entering a second round of vetting for a dwindling list of potential vice presidential nominees, with several black women in strong contention. (AP Photo/Patrick Semansky, File)