Underwood Picks a Fight with Half of Hollywood

The next time you see a celebrity in a political ad, just know Carrie Underwood thinks that person is stupid.

The former "American Idol" found a soapbox, climbed on it, and proceeded to bash the hell out of all sorts of famous people like Timberlake, Stallone, Affleck and Oprah -- for their decision to publicly endorse a candidate for president.

Underwood tells TV Guide, "There is someone I do support, but I don't support publicly. I lose all respect for celebrities when they back a candidate. It's saying that the American public isn't smart enough to make their own decisions ... music is where you go to get away from all the BS."