"...for a war that a majority of Americans now say was a mistake"
I doubt that a majority of Americans believe that. I bet a majority of spineless Euros or Canadians believe that, but not Americans.
Given the overwhelmingly negative coverage of this war -- almost all seemingly aimed at showing the war was a mistake -- I have no doubt that a majority of Americans have serious misgivings about the war. Ours is a decadent society, where political gamesmanship has replaced statesmanship. There's still time to get our act back together, but not much time -- and it will require an honesty and fortitude that seems inaccessible to most Americans.