Thoughts on Iraq

The last two elections were not referenda on Iraq, because they were not framed as a change in direction toward any particular policy alternative, not even immediate withdrawal. There was and is dissatisfaction, but no clear alternatives offered other than "to do something" differently. That can cause people to vote against incumbents, but it doesn't count as a referendum in any meaningful sense.
Yes, with the advantage of hindsight, we should have done certain things differently, including perhaps not going in at all, but it is important to understand what we missed, and when I say "we", I mean almost all of us, because most of us who had much of an opinion did think it seemed like a good idea at the time to get rid of Saddam. (A few of us opposed going in without a constitutional declaration of war, but the odds are that Congress would have voted for one.)
One of the things we didn't miss was the now common view that the people of Iraq are not ready for republican self government. The fact is that 94% of the Iraqi people of all sects are no less ready to govern themselves in peace than most of the people in every other country. They might not have enough sense to vote for "seculars" instead of for "sectarians", but that was something they could eventually have learned. No, what we missed, and it is important, was that remaining 6%.
Or to put it another way, Saddam did indeed have weapons of mass destruction, just not the kind we were looking for. They were that 6%, who Saddam had reduced to a state of barbarism that he very likely calculated would destroy the country when he was no longer around to keep them under restraint. What is happening in Iraq now followed our deposing of him, but would have happened anyway when he eventually died. We were destined to go in to clean up the situation, sooner or later. We just moved up the date by invading.
What perhaps we most missed is the fact that it only takes a small minority of determined barbarians to destroy a civilized society, and it doesn't matter how civilized the rest of the society might be. It is easier to destroy than to create, and no society is really ready to withstand that kind of destructive force. It is worse than most natural disasters. Historically, most societies that have faced similar internal barbarism have either descended into brutal despotism, the barbarians usually becoming the despots, or the barbarians were wiped out, usually along with a lot more innocents. Some of these "burnouts" have reduced the populations of countries by as much as 90%, and destroyed the entire civilized infrastructure.
The trouble is that most Westerners don't really understand bad guys like Saddam. He was expertly playing a "Samson" or "apres moi" gambit. He made Iraq a monument to himself that would self-destruct when he was gone, and trigger a chain of events he expected, with some good reason, would sweep the Middle East, deny oil from that region to the world, trigger a world war for oil and other resources, and bring down the industrialized nations and Western Civilization. We can argue that it would not get that far, but that it was what he tried to set up to happen is all too plausible.

So when it comes to considering our options, let us remember the answer Chinese Premier Chou En-Lai gave to the question, sometimes reported as being asked by Henry Kissinger, "What were the consequences of the French Revolution?" He is reported to have replied, "It's too soon to tell." We won't know whether there is anything else we could do or how it might turn out. History is not a game like chess where we can evaluate the state of the game at any given point. We are flying blind, and while we can try to do the right things, we can never be sure we may not be doing the wrong things, whatever we do.