They usually honor unsubscribe requests per-campaign but if you click "show original" in gmail you may see other brokers who are facilitating emailing you, like action network and NGP VAN. You can create an account in action network with your email and unsubscribe to everything they've got on their website. You can email support@ngpvan.com and ask them to block your email address in their tool.
I have a filter that takes anything that has the word "unsubscribe" in it and labels it "crap" and skips the inbox. Anything that has an unsubscribe link, you surely don't need to read it.
I auto-delete emails that "have the words" ( trump OR congress OR senate OR pac ) AND unsubscribe