Just remember that Fred Thompson was one of the first to support Scotter Libby and setting up a defense fund. He has the heart, mind and sense of many of us here today. Just because he is friends with McCain doesn't mean he agrees with all of his policies. Otherwise he would just put all his energy to see McCain win this thing. I was leaning Rudy G, but Thompson would change my mind. Someone mentioned that even Guiliani was against an early pardon of Libby.
He's friends with McCain, and I think on a lot of issues they agreed. He certainly was with him on Campaign Finance.
However, in 2000 he was actually supporting Lamar Alexander, NOT McCain. He switched to McCain when Lamar dropped out.
I think he's considering running now because he doesn't see a viable candidate pushing the policies and principles that Thompson believes the country needs right now. That he's considering running while McCain is still in the race suggests he sees where McCain has diverged from his earlier conservatism.
Thompson also voted correctly on several things in 2001-2002 that McCain voted wrong about. And Fred is not supporting McCain now, which is telling. He hadn't endorsed him, even before talk of his own presidential race surfaced.