Millions of Americans protested the Iraq war[0]. Globally it resulted in the largest protests in the world at that time. It didn't matter.
Of course you're correct about the zeitgeist of the US at the time, the government, the media and the American right were pro-war and they controlled the narrative. And I have to concede in hindsight there have been times where popular collective action has been effective, just never against starting a war AFAIK. When the US decides it wants a war it seems like there's really nothing anyone can do about it.
[0]https://en.wikipedia.org/wiki/Protests_against_the_Iraq_War
https://en.m.wikipedia.org/wiki/Public_opinion_in_the_United...
The hardest part of my job is connecting Iraq to 9/11 - Bush
These are reddit quality comments that don't belong here.
It's called history