Ok, so the USA invaded Iraq with fear of WMD the announced reason for the extraordinary step of a pre-emptive war. The White House doesn't plan to apologize or say oops as evidence mounts the reasons were bogus.
Question: Would it be a wise move for the Democrats, for example, to issue their own apology. To say, "We voted for this war because we were told there was a serious threat. Learning there was not, we are deeply saddened, sorry and ashamed. How could we have done this?"
Saying this would ask the other side of the aisle, "Why aren't you ashamed, too?"
However, saying you're sorry or ashamed is, for better or worse, un-american. It's weak, too many feel, to admit remorse for errors. You don't do it unless you're forced into it.
You can still feel removing Saddam was the right thing to do. And you can still blame the bad intelligence you were given. But if I make a grave error, even if I make it in good faith because I trusted the wrong people, I still feel remorse over the error. Can the USA? Can some of its politicians?
Back in 1984 I participated in the World Debating Championships. (My team just missed the quarterfinals, alas.) During the finals, the proposition being debated was "The USA should apologize for the American Revolution." One of the most amusing "pro" arguments was that the USA should indeed apologize, and just not mean it. That this was the true American way.