I agree absolutely.  This Democrat thing was focus group tested by the Gingrich gang years ago and spread in strategy memos to the Repugs and their media mouthpieces.  It sounds pejorative, and that's why they do it.

I've said on these blogs more than once that Dems on talking-head shows who sit there and let this go by need instead to stop it dead in its tracks.  ("Excuse me, Senator, I'd like to correct you on something that the rest of us learned in grammar school, and that's the appropriate use of a proper adjective.  It's 'Democratic,' not 'Democrat,' and I think you know that.  So please afford me the same level of respect that you expect to be shown yourself."

Or: "Knock it the fuck off before I smack your teeth down your evil throat."