Sen. Lindsey Graham (R-S.C.) (Photo by Win McNamee/Getty Images)

(CNSNews.com) - Sen. Lindsey Graham (R-S.C.) said he supports President Trump's directive to declassify documents that will explain why the FBI got a FISA warrant to surveil the Trump campaign.

The Mueller report is finished, Graham noted, and the special counsel did not find criminal activity on the president's part related to collusion or obstruction.

"Now I'm insisting that we get to the bottom of this," Graham told "Fox News Sunday."

"I want all the documents around the FISA warrant application released. I want to find out exactly how the counter-intelligence operation began. I think transparency is good for the American people.

"Not one Democrat seems to care. I was the hero when I said let's support Mueller. I wish some Democrat would come forward to find out if the FISA court was defrauded by the FBI and the Department of Justice. So, I support Attorney General Barr to make this as transparent as possible."

Wallace noted that critics of the president's declassification order don't trust Attorney General Bill Barr, fearing that he might "cherry-pick the information to make a case for the president."

But Graham said he thinks Barr can be trusted. Those who do not trust Barr "are worried about being exposed for taking the law in their own hands," Graham said.

"We're not compromising national security here. We're trying to create a system to make sure this never happens again by shedding light on what happened with the FISA warrant process, the counterintelligence investigation. Did they have a lawful reason to surveil President Trump's campaign? Did they lie to the FISA court?

"Every American should want to find that out."

Impeachment would be 'political suicide' for Dems

On another topic, impeachment, Graham said there are no grounds to do it.

"I don't trust House Democrats to be fair. They're trying to redo the Mueller report," Graham said. "They're trying to make up other stuff. And at the end of the day, it will be political suicide for them to impeach."

House Speaker Nancy Pelosi (D-Calif.) "knows that impeachment would be political suicide because there's no reason to impeach the president," Graham said.

So, she's trying to keep the party intact. If she goes down the impeachment road, Republicans take back the House, we keep the Senate, President Trump gets reelected, but her job is very much at risk. So what I think is going to happen here -- I think that she's going to be driven towards impeachment. If she goes down that road, it will be suicide for the Democratic Party. From President Trump's point of view, I disagree with the idea that you can't work with them while they're doing things like this. You have to work with him. If you can't control, Mr. President, what the Democrats do, but you can control what you do, and you need to lead this country to better bridges and roads and lower prescription drug prices. They say no to you, that will help you. They say yes to you, and work with you, that will help the country. So, I don't believe that the idea of working with the Democrats should be taken off the table because they're going too far.

Graham said Judiciary Committee Chairman Jerry Nadler is trying to "destroy" the president. "If I were the president, I would fight Nadler tooth and nail."