I guess you are probably right in citing the reasons people usually give for their support - but I am not sure whether these are actual reasons or mere rationalizations. The hallmark of fascist warmongering propaganda is to project an image of the majority being gravely threatened by some unpopular minority, e.g. Germany was supposed to be threatened by "Jewish or Bolshevist conspiracy," the Serbs were supposed to be threatened by the Muslim minority, and now the US is supposed to be threatened by a petty tyrant in another hemisphere. Fascist aggression has invariably been portrayed as self-defence.
What I find perplexing is why some people believe in this crap, which does not hold water to anyone with even half a brain. Just think, the people who normally buy the most bizarre goverenment conspiracy theory or routinely dismiss the "liberal media" as a bunch of lies, suddenly take an obviously preposterous government and media story at its face value. Something does not add up here. My suspicion is that these folks look for an opportunity to "kick ass" and use these preposterous claims spoon fed by the media as a convenient rationalization to cover up their bigotry and warmongering.
I am not disputing that anti-war protest attracts people from different walks of life, education or income levels, races and faiths. The same can be said about warmongering. The question that I ask is what turns people who live a relatively safe and prosperous lives, who experienced no harm either directly or indirectly into warmongers. I can understand why Palestinian teenangers danced when the twin towers fell, but I do not undestand why US-ers attend a "Bomb Iraq" party (http://www.citypaper.com/2003-02-19/photofeature.html).
Wojtek