One of President Donald Trump's Republican challengers says he'd vote for Joe Biden "in a heartbeat" against Trump in the 2020 general election.

Former Massachusetts Gov. Bill Weld says, "Could I vote for a Democrat? Hell yes. If it's Trump against Joe Biden, I'm with Biden in a heartbeat."

Weld's comments came during an appearance at the CITIZEN by CNN conference. He was joined onstage by former South Carolina governor and congressman Mark Sanford and former Illinois congressman Joe Walsh. They are also seeking the Republican presidential nomination against Trump.