For comparison, here's the May 2007 Des Moines Register poll:
30% Romney
18% McCain
17% Giuliani
7% Thompson
5% Brownback
4% Huckabee
4% Tancredo
1% Cox
1% Gilmore
1% Hunter
12% Undecided
Was that Fred Thompson or Tommy Thompson?
Fred Thompson hadn't entered the fray in May 2007.
Yes, but he was included in most polls, because he was publicly flirting with the possibility of running, just like Palin and Perry are now. He was in double digits in most of the national polls by May 2007.
However, I'm guessing this was probably Tommy Thompson, since it looks like DMR doesn't include candidates who aren't running yet. Just like they didn't include Palin or Perry in this poll.