Rebuilding America Now, a new Super PAC that backs presumptive Republican nominee Donald Trump, hired Alex Castellanos. He previously worked for Mitt Romney and was quietly supporting a Stop Trump effort last fall.

Castellanos is now helping guide Rebuild America Now along with its backer Tom Barrack, who is a friend of Trump. The Trump campaign has not publicly blessed the super PAC.

“I’m worried that we don’t have four or eight more years to wait to change direction,” Castellanos stated, explaining why he decided to join the group after having opposed Trump, according to the New York Times. “This is not about whether the Republican wins or loses the White House. This is about whether we can afford to go in the same direction, and because I’m concerned if we go too much farther we won’t be able to turn back.”

The Super PAC aims to counter efforts by a Super PAC supporting Hillary Clinton, Priorities USA Action.