Donald Trump tore into his former primary rival Sen. Lindsey Graham on Friday, mocking him for refusing to support the presumptive GOP nominee.Turning his vow to unify the party into a jab at the South Carolina lawmaker,that Graham "has shown himself to be beyond rehabilitation. And like the voters who rejected him, so will I."The condemnation comes after Graham flatly refused to endorse Trump earlier Friday, saying he doesn't believe Trump is a "reliable conservative Republican.""Trumpism is not conservatism. That will be obvious to many people,"But Trump dismissed the diss."I fully understand why Lindsey Graham cannot support me," Trump's statement said. "If I got beaten as badly as I beat him, and all the other candidates he endorsed, I would not be able to give my support either.""Every time I see Lindsey Graham spew hate during interviews I ask why the media never questions how I single-handedly destroyed his hapless run for president," he added. "As a candidate who did not receive 1 percent in his own state – compared to my victory at nearly 40 percent with many others in the race – he has zero credibility."