The general refrain from the neoconservatives is that the public is losing faith in the Iraq War for one of two reasons:
(1) The U.S. public has a low tolerance for casualties, and people are getting faint-hearted about a steady stream of killings and woundings.
(2) The evil news media is blacking out the avalanche of good news coming from Iraq that would show how wonderful the war is going. After all, the soldiers over in Iraq (who we all know are perfectly free to speak their minds) say that things are going really, really great.
In reality, there are three main reasons that the Iraq War is losing public support:
(1) The metrics do not suggest we are winning. The estimates for the size of the insurgency are increasing; insurgents are carrying out a greater number of attacks per day than a year ago, coalition fatality rates have been in general increasing since the end of major combat operations, and the security situation appears to be getting worse (Thanx and a tip o' the hat to Jim Henley).
(2) Bush does not have any sort of clear plan for victory. Actual victory will be achieved when we can pull all of our troops out of day-to-day security operations without Iraq falling apart, and progress toward victory will have been made whenever we can reduce our troop levels permanently without the country falling apart.
Nonetheless, Bush has not offered any metrics by which we can judge whether or not the Iraqis are willing and able to defend Iraq so that we can reduce troop levels, and any attempt at a clear time framework is dismissed as "cutting and running," with the statement that we need to stay until the job is done (what that entails is not exactly clarified).
The U.S. willing to take losses, but not if they don't see any progress being made toward the goals for which those troops fought for. Losing troops so that we can keep treading water in Iraq is not acceptable to the vast majority of Americans.
(3) Bush and his administration seem completely oblivious to this. None of their talking points seems to acknowledge that the insurgency is growing nor do they seem to offer any inkling that the administration has determined some sort of parameters by which progress to victory can be measured. Indeed, all of the current talking points amount mostly to "trust us, we know what we're doing."
What Bush has not done, and what he needs to do, if offer some strategic framework for our involvement in Iraq, complete with our actual end-goals, benchmarks for success (benchmarks imply a reduction of troops when the benchmark is reached), and a tentative timetable for the meeting of different benchmarks.
Unless Bush shows the American people that he knows what he is doing, his popularity will continue to fall as longas it has somewhere to go.
That is all.