As of 6/26/07:
Fred Dalton Thompson 27%
Rudy Giuliani 23%
"...Thompson, preparing to formally announce his candidacy, leads the pack in the latest Rasmussen Reports national telephone survey with 27% support. That gives him a four-point advantage over former New York City Mayor Rudy Giuliani who is currently preferred by 23% of Likely Primary Voters. A week ago, it was Thompson 28% and Giuliani 27%. Two weeks ago, they were tied at 24%. Prior to that time, Giuliani had been on top in every weekly Rasmussen Reports poll for five months
Thompson leads Giuliani by 13 percentage points among conservative primary voters while Giuliani leads among moderates.
Among Republicans, 74% now have a favorable opinion of Giuliani. That’s down from 82% in late May. Twenty-three percent (23%) of Republican voters have an unfavorable opinion of the former Mayor. Thompson’s numbers among the GOP faithful have been moving in the opposite direction. Sixty-six percent (66%) of GOP voters have a favorable opinion of the actor while just 18% have an unfavorable view.
Among those with more strongly held opinions, Thompson currently has an edge --21% of Republicans have a Very Favorable opinion of him while 14% have a Very Unfavorable opinion. For Giuliani, those numbers are 18% Very Favorable opinion and 19% Very Unfavorable..." (Read the whole article at Rasmussen Reports)