When I receive a political robocall, I make note of the politician who's the subject of the call and I then proceed to call their campaign headquarters and speak very rudely and sternly to the staff person who answers the call. I've gotten off several calling lists that way- lists that I NEVER asked to be on. It probably doesn't accomplish much, but I don't think it's a wasted effort to call and annoy people who willingly call and annoy me.
In local elections, I can frequently talk directly to the candidate. It's always fun to listen to them stammer and try to make an apology.
Note to politicians: If I want to hear from you, I will contact you. I don't need nor want you calling me and I don't need or want any of your "supporters" calling me on your behalf. I get enough of your foolishness in the media. I don't need to hear it over my phone.