The Bernie Sanders coalition is starting to look interesting.

If you had told me a month ago that he would win New Hampshire by more than 20 percentage points and would barely lose in Iowa, I would have shrugged. It has long been known that he fares very well among white liberal voters in white liberal places, like New Hampshire and Iowa or, later, Oregon and Wisconsin.

But with the actual results in and counted from two states, it is clear that Mr. Sanders is faring much better among less educated and working-class white voters than Barack Obama did in 2008, or than other idealistic liberal candidates like Howard Dean and Bill Bradley did.

The pattern holds no matter how you look at the data. The exit polls show Mr. Sanders doing best among less affluent voters — and it’s not just because young voters, with whom he’s very popular, make less money. The actual returns also show that Mr. Sanders fared well in many of the places where Mr. Obama was weakest, like far western Iowa and southeastern New Hampshire.

Mr. Sanders’s strength among white working-class voters is important because it gives him a chance to overcome the challenge past progressive candidates faced: Well-educated white liberals, the sort who supported same-sex marriage before it was popular nationally, simply don’t represent a large enough share of the electorate to win a Democratic primary. Mr. Obama overcame this by winning black voters by a huge margin in 2008 — something Mr. Sanders has no hope to repeat. Even then, Mr. Obama won the nomination by a hair.