Graham also added that he did not know what Giuliani has found or "what he was up to when he was in the Ukraine," but that he was willing to use the Judiciary Committee to look into Hunter Biden and Ukraine.

"We can look at what Rudy's got and Joe Biden, Hunter Biden and anything else you want to look at after impeachment. But if Rudy wants to come to the Judiciary Committee and testify about what he found, he's welcome to do so," Graham added.