Not sure that you are saying this, but there is a common misperception that prior to Vietnam and the modern media era, there was near uniform public support for all US war efforts. Nothing could be farther from the truth. At the risk of gross oversimplification, any war of choice that incurred any but the most minimal of casualties has raised the ire of a significant portion of the electorate, regardless of the sophistication of the media delivering the casualty reports. Some attribute that to the persistent isolationist strain that is part of American exceptionalism Not sure if that is correct, but sure that history is replete with war protests, the exception really being WWII - that's the anomaly, largely because it was viewed as an existential threat, IMO, which it was. That said, even the Civil War, the paradigmatic existential threat, saw plenty of objection to the bloodshed when the cause against the South appeared to be going nowhere. Sherman's message delivering Atlanta in early October 64 (I think) is attributed with ensuring Lincoln's reelection, failing which he would have been turned out by McClellan seeking peace. Look at the First lines of the Second Inaugural if you doubt:
There is persistent meme in the Conintern to see Bush as some unique victim of malevolence from his opponents, which is absurd from even a recent historical perspective, but nothing is more central to the modern right wing ethos that the victimization shtick.
And not since the Spanish American War has a "war" been sold to the public under such dubious circumstances, with a President taking the lead in the sales process. Before the War, when positive results were expected, his bold leadership was attributed for seeing the threat that others did not. Now that we know that his vision is flawed, both as to the threat and to the cost to address it, the criticism has justly come. The Weekly Standard crowed after the 2002 midterms that Bush had gained the Senate by making the election a referendum on his choice to go into Iraq. When it served his political purposes, the President was happy to take responsibility and praise. When it doesn't, suddenly it's bad manners to be anything but an enthusiastic supporter. That said, I agree that we are in it now and must finish it unless we deem that impossible, which it may be given prior misjudgments