Sen. Jeff Flake, R-Ariz., said in a recent interview that he hopes somebody runs against President Trump in the 2020 election, and that Trump supporters' continued chants of "lock her up" — typically in reference to Hillary Clinton — are "disturbing."

In his retirement interview with C-SPAN, Flake said the chants, which were sparked by Trump's campaign and have continued throughout his presidency, are more concerning than the controversial things Trump says.

"The disturbing thing isn’t so much what [Trump] says anymore, it’s the cheers from people behind him and the chants of, 'Lock her up!' for example that’s just unseemly," Flake said. "It does make me fear that it's going to be a longer process to get out of this than it should be."

While the signature chant often heard at Trump's campaign rallies has been reserved for Clinton, at the president's rally in Iowa on Tuesday night, Trump mentioned Sen. Dianne Feinstein, D-Calif., asking the crowd: "How about Senator Feinstein? That's another beauty."

Moments later, the crowd quickly started up the familiar chant.

The retiring one-term senator said, "Ultimately, voters will again value those who can govern and those who can treat each other with respect."

But, he said, he "fears for the future of the party if we don't remember who we are and what principled conservatism really is. And decency, we've got to get back to it."

Flake said he's not ruling out a run for the White House, but acknowledged he "needs a break," and said he's retiring because of the "political outlook"

FLAKE SLAMS GOP, SAYS HE FEELS LIKE HE DOESN'T BELONG TO ANY POLITICAL PARTY

"It's a tough time to be here," he said. Flake said he "never did warm" to Trump, and to win a Republican primary election in the U.S. right now, "you have to embrace all of his politics."

The Republican Party "is the president's party right now, no doubt," Flake said. "You have to really embrace the president’s policies and condone his behavior and that’s the bottom line right now. But it won’t always be that way, and over time we’ll realize where we need to go."

Flake's full interview will air Oct. 13 at 10 p.m. ET on C-SPAN.