Pres.
Trump's ally Sen.
Lindsey Graham is making the media rounds to defend the President.
He's one of the President's staunchest allies.
The President is facing an impeachment trial in the U.S. Senate.
The Democrats want to bring a witness against Trump: Former National Security advisor John Bolton.
Graham went on Fox News and said Bolton should talk at a news conference, not under oath.
Graham told Fox News' Martha MacCallum that he has "all the evidence I need.