For max effect say the bad news but refer to it as good news.

Then only the swingers will catch on. The fully hypnotized libzombies will nod along and agree with you because they aren't really paying attention. They never were.

Before hanging up ask them to grab a pen and write something down then give a short simple URL like https://joebiden.info/ or something similar. Tell them the best fact checks are all on that page.