I heard both of them with my own ears tell SC voters to vote for Fred.
That doesn’t mean they endorsed him. Pluse, I haven’t seen a transcript yet. I’ve seen a few Romney people telling people to vote for Fred, just as a few Fred people told people to vote for Romney in Michigan.
The word “endorse”, is a well-known two-syllable word. Levin and Rush have national TV shows where they can say whatever they want.
If either of them wanted to say “I endorse Fred Thompson”, they could do so.
Since they have not, it seems disrespectful to pretend they have.