@gollum,
Allow me to introduce you to a place I call Boston, if you want to see left of center politics in the wild.
But either way, why are states blue, versus red (or purple, really; they all are but shh don't tell the media)? Lots of possible factors in no particular order:
- These cities have a mix of races. Walk down streets in both cities and you will see people of every shade. This does not mean, I might add, that racism does not exist. But there is a ton of diversity. Furthermore, you'll see a lot of mixed-race couples in both cities.
- LGBT rights are huge in both places. Welcome to gay marriage, in two of the places where it's just not a big deal for straight couples to see their gay peers wed.
- Both cities have tons of houses of worship, yet religion isn't the biggest thing in people's lives.
- Building on the previous point, both places are loaded with highbrow cultural attractions. Live theater is a lot closer to the center of both cities than auto racing is.
- Both are tech meccas, although Silicon Valley is more of a tech center than both of them. Boston in particular also has a thriving startup scene.
- Both boast world-class universities and attendant hospitals which attract and retain top talent.
- Neither city has a big gun culture.
Consider liberal vs. conservative issues. Do liberals come to Boston or New York because these are gay-friendly areas, or there's stricter gun control, or are these gay-friendly, etc. areas because liberals have moved in? It's a chicken and egg question in some ways, but recognize that, if all of the characteristics of liberals (or conservatives, for that matter) are present in a place, that is going to attract more people of the same political stripe. If it's uncomfortable for people on the other side of the aisle, they might be more inclined to move away if opportunities open up elsewhere, thereby skewing things even more.