Like Iowa, the New Hampshire primary papers over one of the defining cleavages in the Democratic contest: race and ethnicity. According to the exit poll, 91 percent New Hampshire Democratic voters were white — a stark contrast to the two states coming up next on the nominating calendar, Nevada and South Carolina.

But some important divides remain, mostly along age and ideological lines. Sanders was the overwhelming choice of young voters, winning 51 percent of those under 30, and 42 percent of those under 45. Voters under 30 made up roughly 14 percent of the electorate, according to the exit polls, while a little over a third were under 45.

Sanders was much weaker with older voters, capturing 17 percent among those 45 and older, and 14 percent of seniors 65 and older.

Klobuchar’s age splits were reversed on Tuesday: The Minnesota senator only won 4 percent of those under 30, and 7 percent of those under 45. But she cleaned up among the older voters who were the backbone of Biden’s support before his collapse in the early states: She won both those 45 and older (with 27 percent) and seniors 65 and older (with 32 percent).

Support for Buttigieg, meanwhile, bridged the age divide. He won 21 percent of voters under 45, and 26 percent of those 45 and older.

About one-in-five voters described themselves as “very liberal,” and around half of them, 48 percent, voted for Sanders, the exit poll shows. Including those who identified as “somewhat liberal” brings the progressive share of the electorate to about 60 percent, and Sanders won 33 percent of them.

Buttigieg and Klobuchar essentially tied, 27 percent to 26 percent, among the roughly 40 percent who described themselves as “moderate” or “conservative.” Buttigieg (22 percent) had slightly more support among liberal voters than Klobuchar (15 percent).

Much of Sanders’ support was locked in earlier in the race. Only 38 percent of voters on Tuesday said they decided for whom they would vote before this month, but more than two-thirds of Sanders’ supporters said they made up their minds before that.

Not only did 62 percent say they decided this month, but half of voters said they made up their minds in the past few days. Among those late deciders, Buttigieg won 29 percent, compared to 24 percent for Klobuchar and 16 percent for Sanders.

While New Hampshire is a major boost for Sanders and Buttigieg — and gives oxygen to Klobuchar’s — it marked a striking collapse for Warren and Biden.

Warren pitched herself as a unity candidate, but she ultimately had a small core of support with the party’s liberal wing, and no traction with moderates. She won 13 percent of liberal voters — 20 points behind Sanders, and 9 points behind Buttigieg — and captured only 3 percent of the vote among moderates and conservatives.

Biden, the candidate of older voters in polls since he entered the race, won only 12 percent of those 65 and older. His lone remaining stronghold: the one-in-10 nonwhite voters in the primary, among whom he won 16 percent of the vote.