FRED THOMPSON HAS NO PRINCIPLES. Note the plural. He does, judging by his website have one principle -- federalism. It's the only thing listed in his "principles" page and it's mainly a long, pedantic essay that answers the question "so what is this federalism thing anyway?" There's almost no discussion of the issues except for, bizarrely, immigration which is a federal issue if there ever was one:
The recent immigration bill was a case in point. That bill failed, and it failed for good reason. The federal government simply had no credibility on the issue.