While he admits he mostly supports President Donald Trump, Sen. Lindsey Graham, R-S.C., called the troop withdrawal in Syria "the biggest mistake of his presidency."
"I am going to defend this president as hard as I can," Graham told Gray Television's "Full Court Press with Greta Van Susteren" in an interview Thursday which will air Sunday. "I like what he's doing most of the time.
"But when it comes to Syria, I think it's the biggest mistake of his presidency," Graham said. "It's going to have a detrimental effect on our ability to recruit partners in the future. Iran will be the biggest winner. And we've got to stop it before it's too late."
President Trump had said earlier this week, upon hearing of Graham's criticism of his Middle East foreign policy, that Graham wants to be in Syria and in the middle East for "3,000 years."
Graham brushed off the counterattack, saying differences of ideas are permitted in the United States, unlike China and Russia.
"Leaving them alone is a certainty to get attacked again," Graham said of a vacuum that could lead to another rise of ISIS. "That a small portion of our troops working with people on the ground keeps us safe. I'm not going to say otherwise because President Trump disagrees with me."
Graham then praised the president for having the "thickest hide" amid criticism and attacks – even from him as an ally.
"He's got the thickest hide I've ever seen," Graham said. "You work with him one day, fight him the next. I don't agree with what he's doing in Syria, I want him to be successful, and I think he sees that."