I saw it differently, he seemed to be running a pretty smart campaign and was building momentum, but the media kept ambushing him at his key moments of success,with those rumors. Romney was linked to those rumors.
There are old threads here about those times.
Thompson didn't care what the opposition said or did. He had the right answers on just about everything and was very comfortable saying what he thought. If Thompson's heart and mind and been in it, he would have won the nomination and probably POTUS.