WASHINGTON (AP) — 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.

Democrats with knowledge of the process said Biden’s search committee has narrowed the choices to as few as six serious contenders after initial interviews.

Biden, who has already said he will pick a woman as his running mate, is facing increased calls from Democrats to put a woman of color on the ticket — both because of the outsize role that black voters played in Biden’s road to the nomination and because of the reckoning over racism and inequality roiling the nation following the death of George Floyd.

Terry McAuliffe, the former Virginia governor and former Democratic National Committee chairman, said that while Biden’s choice was likely to be “all about personal chemistry,” it would be “exciting for the party” to have a black woman on a major party presidential ticket for the first time.

Harris is the lone black contender who has won statewide office, notable experience given Biden’s emphasis on wanting a partner “ready to be president.”