With SMS, you can reply with STOP and it should take you off that list. Repeat for a few campaigns and hopefully you are done for that election cycle and get less/none in the next cycle.
This was actually the only political spam I got for most of my life until my wife got mad at me for never voting and I finally registered. Then the Democrats must have trawled the public records and they started spamming me, too. I'm so glad to have participated in democracy. Things are clearly much better in 2022 than in 2019 because I voted.
> I get very little of it from Republicans but lots of it from Democrats.
Have you donated money to Republicans? How about Democrats? What are you registered as? What have you been registered as before?