- never signed up for anything like this,
- never donated to or signed up for emails from the DNC, et al.,
- political texts like this come all the time, and
- I hesitate to reply “stop” because I don’t want them to know this is a live number (is my instinct here outdated/inapplicable?)
It seems to be the SMS integration that MacOS can have when you also own an iPhone.
You can do the same on Android on any other operating system