How would the Republicans respond if Bush came out and admitted that he was completely wrong?

Would the Republicans turn against them even though it was his policies? One thing he recently came out and said was he would never of gone into Iraq if he had known there were no WMD's. So what does that say about his supporters that still contend their were WMD's and that the war was right? You've got your President admitting there were none and that he wouldn't of gone if he had known there wasn't any.