[Omaharocks]

I'd say Minneapolis is the obvious candidate here. Also maybe Baltimore? Though it doesn't have as strong a progressive bent, it's in one of the more liberal states.

In other parts of the midwest, I think you could make a case for Milwaukee, but Madison is no longer affordable.

Others, I'd say yes, perhaps Tucson and Albuquerque, which are fairly interchangeable. But Tucson is easier to move to/find a job from out of state - NM is very insular (part of why the culture has remained so unique).

Outside of ABQ and Tucson though, the pickings are very slim for affordable and liberal places in the west - the liberal college towns or progressive small cities tend to be very expensive.

In the south, I first thought of the research triangle, but i think prices have gone up to the point where it's no longer affordable.