Jim DeMint’s decision to endorse Mitt Romney is a big deal in South Carolina. Originally a fan of George Allen, DeMint is said to have been leaning toward Romney for quite a while, but this final decision will likely be a great help. “You have Lindsey Graham for McCain, and Henry McMaster for McCain, and now you have a major official saying, ‘No, I’m not with them, I’m for Romney,” says one experienced Republican source in South Carolina. “It’s important because of that. It’s also important because Romney’s Achilles heel has been the Mormon issue, and when you have a conservative senator who is admired by the religious right, that helps put aside the religion issue.”

Still to come: A decision from South Carolina Governor Mark Sanford. He was a big McCain supporter in 2000, but some observers find it interesting that he hasn’t yet made a public commitment this time.