Your number is on a list of real numbers with real identities associated with them that was sold to them. Data brokers sell this information daily. They already know your number is real, but in order to comply with the law, they have to provide you with a legitimate option to opt out, so you will actually stop receiving correspondence from them if you ask them to stop (it is legally required). If not, they could be subject to a fine, but you’d obviously have to file a complaint with the relevant regulatory body for that.
If you do not attempt to opt out, they cannot be fined for spam if this is part of a legitimate donation campaign. If you don’t reply, they will continue sending messages to you in the future. It costs them almost nothing to do, so even if they didn’t know your number was real, they would do it anyway. Most of the people who donate from these messages don’t reply through text message anyway. And if this were an actual scam, then there is nothing they gain from receiving a text back so long as you do not open their link. But again, in order for legal action to be taken (since these political reach outs are legal and not spam so long as there is an option to opt out), you must first try to opt out.
EDIT: Feel free to block the number after opting out. If they are legitimate (though the name is really fishy), then opting out will remove your number from all of their solicitors’ lists, so you won’t get texts or calls from different numbers working for the same campaign. Again, replying doesn’t give them anything even if it is a scam, as your number was obtained from a real list sold to them by a data broker; they already know the number is in service. Just don’t click the link in the text, and don’t reply with anything other than stop.