Although many Republicans are sticking with President Donald Trump in the fall election, some conservative voices are refusing to vote for the incumbent, and instead have declared their support for presumptive Democratic nominee Joe Biden.

Most notably, the Lincoln Project PAC, a Republican-backed group opposing Trump's re-election, have expressed their support for Biden. Conservative attorney George Conway, the husband of Trump’s assistant Kellyanne Conway, revealed in March that he had donated the maximum allowable amount to Biden’s campaign. Steve Schmidt, a campaign strategist who ran John McCain's 2008 presidential campaign, also backs Biden.

Meghan McCain, the daughter of the late Arizona senator, has said she will vote for Biden, saying “politics is personal” for her. Trump has routinely mocked John McCain, saying in 2015 that he was “not a war hero.”

In June, former Secretary of State Colin Powell announced his endorsement of Biden, on CNN's “State of the Union.” Powell, a Republican who served in George W. Bush's cabinet, said Trump had “drifted away” from the Constitution. Powell also supported Democrat Hillary Clinton in 2016.

Carly Fiorina, the former CEO of Hewlett-Packard and a former Republican presidential candidate, said she would vote for Biden due to his character.

“I am encouraged that Joe Biden is a person of humility and empathy and character. I think he’s demonstrated that through his life. And I think we need humility and empathy everywhere in public life right now. And I think character counts,” Fiorina told The Atlantic in June.

Bill Weld, the former Republican governor of Massachusetts, has suggested he would back Biden over Trump. “Could I vote for a Democrat? Hell yes. If it's Trump against Joe Biden, I'm with Biden in a heartbeat,” said during a CNN conference in October.