Interesting, I'd have thought it would be a more conservative thing. Keeping money local, protecting local businesses. Maybe that's why they're moderately popular? They cross the political divide.
These affinities have shifted many times in American political history. For example, Lincoln was a Republican.
The Fed can print 4 trillion dollars for Wall St and people don't care. That's getting pretty close to half of GDP for one year (at the time). Hundreds of millions of people's work product...
If they're going to print money like that at least inject it into the economy by buying stuff like free healthcare or education.