Scale problem
There's a Rorschachesque resemblance at the continental scale, but when you zoom in (in either the militia map or a zoomable political orientation map) the dichotomy between city and country holds up. I found one correspondence (militia and Occupy) at Albuquerque, but elsewhere the militia are plotted in the country, and Occupy protests plot in the city.
Course, you might ask who'd hold a protest in the country anyway, but I think that's a red herring. The average Occupy protestor is as distinctively liberal as the average tea partier is distinctively conservative. It's more than just a convenient concentration of people.