I send it back unopened. I mark it ‘refused mail’. I believe they than have to pay the return postage costs. if so that is just a few less coins for them to contribute to the anti-second amendment orgs. and the anti-hunting groups.
Better to send it back in their prepaid return envelope stuffed with what they sent and any other junk mail handy. It’ll help the USPS and cost AARP extra.
Started doing this to RNC and any other junk mailers and damn, now they don’t pester me at all.