Eh, public polling was pretty mixed. If you ask “invade Iraq, yes/no” the polls showed a slight yes advantage. But if you ask about unilateral invasion without UN approval it cratered to like 31%. Also, some polls showed large majorities thinking the war was a mistake by early 2004.

Support for how bush was running the war was generally lower than support for the war. This all seems to line up with “the public does care about foreign policy, but it’s very far down the list of priorities” theory of voter behavior.