I was looking on another thread, and somebody said Thompson's problem was that he'd had a lot of extra-marital affairs. I don't know anything about it one way or the other, or whether they were speculating or had seen articles or what. Thompson's senate committee was hot on the illegal campaign contributions to Clinton and Gore (remember the Buddhist nuns testifying that they had been given thousand dollar checks to contribute to Gore at the Buddhist temple?), and suddenly, all that got dropped and they went off on that silly Monica Lewinski trail, and Thompson declined to run for re-election. This was at the time all the FBI files were in the White House.
It could all be coincidence, or there could be something in Thompson's FBI files, and the Clintons also used to have private investigators dig up dirt on people who were causing them problems. If Fred stays silent and out of the race, there's possibly a reason. It could be that he just doesn't want to deal with politics anymore, or the fact that there's something he doesn't want brought up.
There were 900 FBI files. I would be surprised that one of those happened to be Fred Thompsons, as opposed to one of the other 60 million conservatives in the country.
He divorced in 1985, and remarried in 2002. He could well have had affairs. He could have cheated on his first wife, but that would have been a long time ago (more than 20 years). He probably didn't cheat on his current wife, so I doubt his actions in the senate had anything to do with dirt about cheating.
I would want to know why he divorced, and whether he was sleeping around in the last 15 years or so. It's one of the things I like about Romney -- he's got what looks like a really clean life.