I have a feeling more Republicans think this in private than said so in public:
Some have drawn a contrast between the sobriety of tone of Petraeus and Crocker and the perhaps over-positive tone of the president's remarks. The trouble was, if the president were to speak at all, he had no alternative to this tone ... which may suggest that he ought to have waited until the first signs of success in Anbar have been confirmed as something larger and more permanent.
Compared with the larger picture, the domestic partisan repercussions of the president's decision to up the bet in his dollar auction in Iraq are trivial. But it doesn't make a huge amount of sense for an American political party to bind itself to a war it obviously cannot control. If the current predictions turn sour, the verdict on the Republicans and their reflexive deference to a clearly overwhelmed war-president may be severe.