The problem is that SPAMing works for US politicians, so they include exceptions in various anti-spam legislation for political calls / texts, and survey calls / texts.
The solution is to recognize that our legislators have a severe conflict of interest, and instead ban these via ballot initiatives. Of course the politicians will whine and complain, but once the voters speak, they will comply.
Has there ever been a "Stop political texts" ballot initiative?
It doesn't need to work, it might even NOT work, may even be counterproductive; it just needs to be protected and they think it works.