With wins in 7 states and DC, Biden closes in on nomination

People wear masks as they wait in line to vote at a voting center during primary voting in Washington, Tuesday, June 2, 2020. (AP Photo/Andrew Harnik)

Voters in the Pennsylvania primary wait to vote outside the McKeesport Public Safety Building in McKeesport, Pa., Tuesday, June 2, 2020. (AP Photo/Gene J. Puskar)

Darren Atkinson wears a mask as he wipes down a voting booth at a voting center during primary voting in Washington, Tuesday, June 2, 2020. (AP Photo/Andrew Harnik)

A voter fills out his ballot as a woman waits her turn during primary voting at the public safety building in McKeesport, Pa., Tuesday, June 2, 2020. (AP Photo/Gene J. Puskar)

A voter, right, checks in with an election worker before casting her ballot in the Pennsylvania primary in Philadelphia, Tuesday, June 2, 2020. (AP Photo/Matt Rourke)

People wear masks as they wait in line to vote at a voting center during primary voting in Washington, Tuesday, June 2, 2020. (AP Photo/Andrew Harnik)

Voter Christina Tremblay, of Providence, R.I., steps out of a voting station at the historic Casino function hall at Roger Williams Park, Tuesday, June 2, 2020, in Providence. In-person voting is being offered at a reduced number of locations for voters who missed the deadline to request a mail ballot. (AP Photo/Steven Senne)

Marty Goetz, left, unpacks a bottle of alcohol from the COVID-19 prep kit as they start to set up their polling place Monday, June 1, 2020, for the voting for Tuesday's Pennsylvania primary in Jackson Township near Zelienople, Pa. (AP Photo/Keith Srakocic)

Democratic presidential candidate, former Vice President Joe Biden speaks in Philadelphia, Tuesday, June 2, 2020. (AP Photo/Matt Rourke)

People wear masks as they wait in line to vote at a voting center during primary voting in Washington, Tuesday, June 2, 2020. (AP Photo/Andrew Harnik)

Marty Goetz, right, and Diane White, prepare the voting screens as they start to set up a polling place Monday, June 1, 2020, for the voting for Tuesday's Pennsylvania primary in Jackson Township near Zelienople, Pa. (AP Photo/Keith Srakocic)

Jenn McCullough, wearing a protective face mask as a precaution against the coronavirus, steps from the voting booth after casting her ballot in the Pennsylvania primary at the Kimmel Center in Philadelphia, Tuesday, June 2, 2020. (AP Photo/Matt Rourke)