See here for pictures of random supporters of Presidential candidates. The Berniebro stereotype is eerily real, with the men mostly being bulky and bearded.

I have often wondered how Hillary Clinton won the Massachusetts primary. Massachusetts’s demographics aren’t too different from those of Oklahoma (which had the same type of Democratic primary as Massachusetts, though in Oklahoma independents were not allowed to vote in the GOP primary), and, if anything, non-Asian minorities comprise a greater share of Oklahoma Democratic voters than they do of Massachusetts Democratic voters. The answer was mostly (but not entirely) that the Clinton vote was strongly (but by no means perfectly) correlated with population density, with people living in places with a larger population density tending to vote for Clinton:
The obvious exceptions are towns like Greenfield (72% Sanders), a town with a more elderly, politically independent, white, and poor population than the rest of Massachusetts, Salem (56% Sanders), a somewhat lower-income White-majority town, and Maynard (53% Sanders), a strongly white middle-class area. Other exceptions include super-rich suburbs like Lincoln (60% Clinton), which, not coincidentally, were some of the only places in Massachusetts to vote for Kasich in place of the vulgarian. Indeed, every place in Massachusetts Kasich won other than Amherst (college town; strongly Democratic, median age 22) and Mount Washington (a 100% White negligibly-settled area) went for Billary. The most Clinton-leaning places in Massachusetts were Lawrence (heavily Hispanic), Wellesley (well-educated rich suburb, one of the most anti-Trump places in Massachusetts), and Weston (rich suburb, went for Kasich).

So Massachusetts went for Clinton instead of Sanders because it was too filled with rich suburban elitists and urban people. Oklahoma went for Sanders instead of Clinton because independents were not allowed to vote for the vulgarian and because there were nowhere near enough rich suburban elitists and urban people in Oklahoma to swing the primary election to Clinton.