This implies that there is some significant chasm between the "putative leftists" and "ordinary people". I know this is a common trope of Faux News (latte sipping liberal elite and all that), but I just don't see it where I live. I'm a leftist; I have kids, economic challenges, bills up the wazoo, worries about neighborhood crime, etc, etc. Sure, I disagree with many of my neighbors about the benefits of socialism, but I'm already "engaged" with them at school meetings and neighborhood meetings and block parties. At least in my corner of the woods (Portland OR), there's no dramatic segregation of the leftists from "ordinary people" (however you define them). In fact, I'd go as far as saying that leftists are ordinary people.
Now, residential segregation based on race and social class is another story--
Miles