Bush II solidified himself with Iraq, even if it seemed that a slim majority of Americans were against it by November 2004.
I don't think that's right. I think 9/11 and the invasion of Afghanistan (and the fact that there were no followup terrorist attacks on US soil, allowing Bush to claim that "we're winning" the War on Terror) solidified Bush. Iraq was probably a net negative for him by November 2004. Though I guess it's possible that with no Iraq War, the Dem. primary contest would have gone differently, and the Dems might have nominated someone more electable than Kerry.
I'd say that the unpopular part of war is American casualties. Bombing isn't unpopular, because few of the American pilots will die. But occupying armies can lead to American casualties, and that's what can be politically risky.
Trump's foreign policy rhetoric tends to be Jacksonian. He doesn't care about democracy promotion or nation building, so he's likely to bomb places without leaving occupying armies, which presumably will minimize the domestic political blowback.
