6 highlights from the fourth Republican presidential debate

DeSantis vows to 'clear out' DOJ

DeSantis described the actions of the FBI and the U.S. Department of Justice related to the Trump-Russia probe as "one of the biggest abuses of power in the history of our country."

He cited the yearslong investigation that put a damper on much of the Trump presidency as evidence that "these agencies need to be cleaned out."

"With me, you'll have a new FBI director on day one. We're going to clear out the DOJ, the IRS, all these places," he vowed. "Buckle your seatbelts. There's going to be a new sheriff in town."

DeSantis offered himself as a younger alternative to Trump and raised questions about the impact of his advanced age. When asked if he thought "Donald Trump is no longer mentally fit to be president," DeSantis replied, "Father Time is undefeated." The Florida governor rejected "the idea that we're going to put someone up there that's almost 80, and there's going to be no effects from that."

"We all know that that's not true," he stated. DeSantis portrayed his candidacy as an opportunity to embrace "a next generation of leaders and really be able to move this country forward." He said Americans must elect "a president who can serve two terms."