From NBC's Mark Murray
As we wrote earlier today, McCain could be the biggest loser with Fred Thompson establishing a "testing the waters" committee, because he will begin gobbling up GOP money that McCain needs for a strong 2nd quarter fundraising performance. But NBC/WSJ pollster Neil Newhouse (R) tells First Read that Thompson pulls more from Giuliani -- at least in the polls.

In the April NBC/WSJ poll, Giuliani led McCain among GOP voters, 39%-24%, with Romney at 12%. But with Thompson on the ballot, Giuliani was at 33%, McCain at 22%, Thompson at 17%, and Romney at 12%.

Moreover, among GOP voters who said they were "dissatisfied" with the GOP field were initially voting for Giuliani by 29%-25%-11% over McCain and Romney. But on the second ballot, those who said they were "dissatisfied" with the field had Thompson out in front 29%-22%-20%-10% over Giuliani, McCain, and Romney.
 
Says Newhouse: "So, it appears Fred pulls more from Rudy ... whose support has been buttressed by GOP voters who are not all that satisfied with the GOP field."