MattD, are you sure the waitress is not the same person you met during that Betty Boop Doll story of yours? (Topic: I felt so Smug)
Anyway: Something similar happened to me when I was dining out with my sister, the service was pretty damn close to open hostility (the restaurant in question being an Angus Steak House in London - one of the slightly pricy chains of restaurants) I suppose they don't like young people or single guests - which is unfair, or, maybe in your case, conservatives, for which I don't blame them.
They DID serve elderly couples and families with much enthusiasm, though, which really pissed me off. (The most annoying thing: We wanted to go to the cinema afterwards, but as they were so painfully slow, we were far too late) Actually, I wouldn't have left a tip, had it not been automatically included in the bill (cheeky bastards!)
Anyway: While I feel treating me this way was completely undeserved, I cannot help but laugh at the idea that it happened to you. Who knows, maybe she (your waitress) is now posting a topic about the story on another internet forum, beaming with pride at her achievement of annoying (and humiliating) a lonely conservative......