I never met the man. In fact, I've never met any of the candidates. But after seeing his stage presence on TV, both in the debates and on Bill Maher's show, I concluded in about 10 seconds that he didn't have the aura to become president. It's something intangible. I can't tell you what he lacks, I just know he lacks it.
Graham might be a wonderful Senator, but he just doesn't stand out as a LEADER. That more than anything doomed his campaign from the start.