Sen. Lindsey Graham (R-SC) on Sunday argued that President Donald Trump should be allowed to "rehabilitate himself" after he incited a mob to attack the U.S. Capitol.

CBS host Margaret Brennan asked Graham about Trump's impeachment trial during an interview on Face the Nation.

"If you believe he committed a crime, he can be prosecuted like any other citizen," Graham insisted. "Impeachment is a political process. We've never impeached a president once they're out of office. I think this is a very bad idea."

"That doesn't mean that what happened on Jan. 6 was OK," he added. "It means this impeachment, in the eyes of most Republicans, is an unconstitutional exercise. The president's behavior in my view is not a crime but he can be charged with one if people think he committed it because he's now a private citizen."

Brennan reminded Graham that Trump "was impeached while he was still in office."

"When you can't argue a case on it's merits, you argue on process," the CBS host said. "And that's what Republicans are doing right now."

"Bottom line: the impeachment articles I think are unconstitutional because the president is in Florida," Graham countered. "So this is not process. The Constitution, I think, is being flagrantly violated because when it comes to Trump, there seems to be no end to all of this."

Brennan pressed: "Does any of that deserve a reprimand?"

Graham suggested that Trump will faces consequences because he "will have a place in history in all this."

"I think I'm ready to move on," the senator said. "I'm ready to end the impeachment trial because I think it's blatantly unconstitutional."

"And as to Donald Trump," he continued. "He is the most popular figure in the Republican Party. He had a consequential presidency. Jan. 6 was a very bad day for America and he'll get his share of blame in history. But I do believe in 2022, the Republican Party is going to come roaring back because our friends on the Democratic Party -- on the Democratic side are going to change immigration policy to have caravan after caravan hit our borders."

"You still believe President Trump is the best face for the Republican Party?" Brennan asked.

"Yeah!" Graham replied. "I think Donald Trump's policies serve the country well. I think Donald Trump has to rehabilitate himself as a politician."