Former Michigan GOP Rep. Fred Upton has endorsed Democratic presidential nominee Kamala Harris over party nominee Donald Trump, of whom he's been a critic.

Upton, a former House Energy and Commerce Committee chairman, on Thursday told the Detroit News that Trump, a former president, is "divisive" and that he has "not changed his colors."

"He's still talking about the election being stolen, trashing women left and right," he said, while at a campaign event in battleground state Michigan with Democratic vice presidential nominee Minnesota Gov. Tim Walz. "We need to move forward, and that's why I'm where I am."