Conservatives who live in liberal areas, or move in liberal circles, on the other hand, tend to either be pretty quiet about politics or, if trying to suss someone else out, employ shibboleths to see if the other party is a member of the tribe.
I don't have a go-to shibboleth for this purpose. I suppose that something noncomittal and sneaky, like "Are you a fan of David Mamet?," might work. Hey, you might just mean his movies and plays. Alternatively, you might mean his recent political conversion to conservatism. A member of the tribe might pick up on that last bit and say something like, "I've become a bigger fan lately."Maybe they should just go with a hanky code.
(There's a whole Vince Vaughn section at the link, for those of you who like it rough.)