Look, this is just politics... we all believed the polls when GWB was at 90%.. he stood up for something then. The admin needs to get proactive and get ahead of these issues. They should have been ahead of the Senate with a withdrawal plan. Just tell the American people that it's time for the Iraqis to take back their country.
Of course it's going to be bad... our forces are the best trained in the world, but if we're going to wait until the Iraqis are anywhere near as good as we are, we'll be there forever.
Your analysis is correct... but this is what happens when an admin. turns negative (no matter how justified). The "attack mode" of discourse sends everyone back to their political base camps, with those in the middle being mostly influenced by current events (which haven't been very good).
But remember, the 90% of Americans who approved of GWB are by and large STILL THERE. They just need to see the president they saw right after 9-11.
Polls, schmolls. GWB just needs to stay focused on crushing the Islamofascists, getting Iraqi forces ready to pull their own weight, and slamming critics who undermine morale when we are at war. This war is much larger than Iraq, and will continue long after that country is wobbling around on its own semi-democratic legs.