If it's from a known Democrat I hang up. If it's from someone that's running in a non party race (e.g., State Supreme Court or Circuit Court, etc.) I listen. In fact, one helped me to decide about a supposedly Non partisan "Independent" whom I knew nothing about running against a seated superior court judge here....ordinarily I'd have voted against the incumbent, but I found out the "Independent" is really a Demoncrat who won't admit it and has accepted donations from "amnesty for illegal aliens" Overall, if it makes the Demoncrats upset, then I AM FOR IT, PERIOD.
Let the Democrats talk all they want to you; ask them questions. Pretend you're interested. All that time spent with you is less time trying to brainwash someone else. :)
Actually I got called by a good friend who was soliciting votes for the Democrats. We chatted for a while, and I felt virtuous, because I was eating up time he might have used to call someone else, plus we had a nice talk.