I don't think the average American would even be able to quantify an actual communist politician. The political metric of the average person in response to politicians is idiosyncratic and largely determined by stuff on TV.

Americans don't care about policy or if it actually gets implemented. They care about what the TV shows and they get mad if they see a black person. That's it. A communist would only register to them as a Democrat or a Republican depending on which one they hate the most.

I've been a self identified communist for over 20 years and the usual response is either confusion, vague curiosity, or they identify me as liberal and/or conservative based on which Facebook memes they just saw.