I think that you're going to have to prioritize your list. Rather like the old film maxim "You can have it good, you can have it fast, you can have it cheap. Choose any two."

Amherst, MA is nice and liberal and tolerant, but it gets really cold there. Iowa City, IA, is liberal, tolerant, and cheaper than Seattle, but is nowhere near water or mountains. San Francisco and the surrounding area is close to mountains and water, warm, and liberal, but it's beau coup bucks to live well there. Parts of Florida have the same issues as San Fran, and there are no nearby mountains. Good luck, though.

If I were you I'd want to move to the south of France, or Italy or Spain. There's all sorts of web sites and books for how to become an expat, dealing with immigration and finding a job. Seems like if you're going to go to all the effort to up and move and you're willing to shop around for anyplace, you might as well get health care and real rapid transit along with escaping the teabaggers.

Sedona, Arizona is surprisingly liberal for such a frighteningly conservative state. It's also beautiful and set right in the mountains and near the water. Public transport may be a problem, since we're not talking about a big city here. You'll need bikes, or a car, depending on how close you are to work and school. The only other problem is the overabundance of crystal-rubbing, new-agey cheesiness, but if that's your thing, you'll do fine. It's good for your aura or whatever.

If public transport and city living are must-haves, you might try Boulder, Colorado, or even Denver. Though they do get colder in the winter due to their higher elevation and latitude.

Maybe Bend, Oregon if you could stand winters that are actually cold. But, Bend does not get the amount of rain that this side of the mountains gets. Also, I doubt that Bend has good public transportation, because it just isn't big enough.

Bend is hot during the spring and summer, it is right near a bunch of mountains, it is developing into a kind of progressive area I think...at least I know some people who live in the area and they are progressive types. I don't think they would live in a teabagger area. I don't know if it has much water around...it is Central/Eastern Oregon. There are a lot of outdoorsy things to do there.

The one catch, of course, would be the cold winter months, but it seems that most places (aside from like California or Florida) that are warm/hot in summer, tend to also go into cold in winter.

You could also try someplace in Arizona or those parts I guess if you really want only heat, but I'm not sure if there are many progressive places down there. Maybe you could be the first??? Even in winter Phoenix is warm, but you'd have to get used to seeing the landscape in beige. :(

California is beautiful and has good temps if you like warm...at least in some places, but yah, it is very expensive, and not sure of the culture/progressiveness, but it seems pretty progressive in some areas.

Port Townsend! They're partially in the rainshadow of the Olympics, so their climate is slightly drier than Seattle's, and you can't find a friendlier and more liberal town than PT. Ditto Friday Harbor, although living on an island can get old.

Your talking about the Bay Area then. Sanfran, Oakland, Berkeley, All have great public transportation from the BART the bay area rapid transit trains that frequent the area.

Its progressive. Near water. Mountains for hiking are all around, the nearest Mount tamlaipais which is only about a 1/2 hour drive from the city. With yosemite only 3 hours away for longer hikes.

Oh and did I mention Warm???
If you live in the east bay, Berkeley or Oakland, you will be in sunlight almost all year, and definately wearing t-shirts for about 6-8months of those.

Cheap??? Man you sure want it all! Well if you want it cheap, you'll have to live in oakland, its cheaper but not quite for the right reasons, lower standards and crime definately bring the rent down, but I'm not sure thats the best place to raise a kid... I would stick to either bekerley, or a nearby city like el-cerrito, for excellent living, progressive, warm, safe, but less cheap.

Sometimes you can't have it all... But 5 out of 6 aint bad!

Can you be more specific about the warmness you desire?

To some, Seattle is never cold. Yet others bundle up in six layers when it dips to 30°F outside. People from warmer climates will complain that our summers are "cold" since reaching 90°+ is fairly rare. What type of cold is your partner trying to avoid? What are the temperature limits you're seeking?

Someone below mentioned San Francisco, but that place can be "cold" to some people. SF has, on average, only 28 days a year in which the temperatures exceed 75 °F .

Have you already lived in other places/climates? What about them didn't you like?

Not too much rain, not too cold, plenty of sun, water, mountains, and lefties...You are basically describing the central California coast, somewhere between Santa Barbara and Santa Cruz. Got bucks?