Since there's no way to tell PAC texts from actual candidate-funded texts, and the PACs seem to now be the vast majority, I always hit the checkbox to block and report as SPAM to my telco. Not that it'll help much but if it's an actual candidate, the telcos whitelist them anyway (because of course politicians passed a law that requires them to), and if it's a PAC maybe it'll burn their SIM farm number pool a little faster, costing them more.
If you're on Android, I highly recommend: https://github.com/aj3423/SpamBlocker. The UX is a little obtuse to set up the first time (ask your LLM) but once set up it works great.