As Lindsey Graham points out, he's polling well below Ben Carson, a man who said he once attempted murder.
"On our side, you've got the No. 2 guy tried to kill someone at 14 and the No. 1 guy is high energy and crazy as hell," Graham said. "How am I losing to these people? Just look at Donald Trump's foreign policy. What is it? What's he going to do about ISIL? What is it? What is it? What is his game plan to destroy ISIL? Does anybody know?"
I'm not as concerned about Trump's lack of a plan for destroying ISIS as I am his racial demagoguery or Ben Carson's batshittery, but I digress.
Why is Lindsey Graham losing to these people? Because the Republican party has shifted dramatically further to the right than Democrats have shifted to the left. The parties are not equally polarized.
There was a time not very long ago when Lindsey Graham could have been counted among the wingnuts, but he's more or less a moderate by today's standards. Being a simple warmongering neo-con is no longer enough. Republican primary voters aren't satisfied without a sufficient dose of white resentment.