On Tuesday, as expected, Sen. Bernie Sanders won the New Hampshire primary, cementing his position as the Democratic front-runner for president. With 97 percent of the expected vote counted, Sanders had 26 percent of the vote, while former South Bend, Indiana, Mayor Pete Buttigieg had 24 percent. The big surprise of the night was Sen. Amy Klobuchar, who finished third with 20 percent. After those three, there was a big drop-off: Sen. Elizabeth Warren finished fourth with 9 percent, and former Vice President Joe Biden ended up fifth with 8 percent.

So how did Sanders win? According to the exit polls, he racked up big margins among demographic groups that make up a good chunk, but still a minority of, the Democratic electorate. Crucially, though, he was still able to win because the rest of the electorate was split among his rivals. For example, “very liberal” voters made up just 21 percent of the New Hampshire Democratic electorate on Tuesday, and Sanders easily beat out Warren to win that group. He tied Buttigieg for the lead among the much larger “somewhat liberal” group, and Buttigieg and Klobuchar split the “moderate” vote.

Buttigieg and Klobuchar split moderate voters Share of respondents who voted for each candidate in the 2020 New Hampshire Democratic primary by ideology, according to preliminary exit poll data Candidate Very liberal (21%) Somewhat liberal (40%) Moderate (36%) Conservative (3%) Buttigieg 15% 26% 28% 21 Sanders 48 26 16 11 Klobuchar 9 19 26 19 Warren 19 10 3 4 Biden 4 8 12 6 Steyer 1 5 4 4 Yang 3 3 3 4 Gabbard 1 1 5 18 Sample size is 2,935. Not all candidates are listed on the exit poll. Source: ABC news/Edison research

Similarly, people between the ages of 18 and 44 made up just 37 percent of the electorate, and Sanders crushed Buttigieg among this group. But the 63 percent of voters aged 45 or above split nearly evenly between Klobuchar and Buttigieg.

Sanders won with younger voters Share of respondents who voted for each candidate in the 2020 New Hampshire Democratic primary by voter age, according to preliminary exit poll data Candidate 18-44 (37% of voters) 45+ (63%) Klobuchar 7% 27% Buttigieg 21 26 Sanders 42 17 Biden 5 10 Warren 11 9 Steyer 3 4 Gabbard 4 3 Yang 5 2 Sample size is 2,935. Not all candidates are listed on the exit poll. Source: ABC news/Edison research

Continuing the pattern, a full 61 percent of voters said they made up their mind on whom to vote for this month; 31 percent of this group went for Buttigieg (who won the most delegates in Iowa), and 23 percent went for Klobuchar (who had a good debate performance on Friday). However, among the 38 percent who made up their mind before this month, Sanders won a whopping 43 percent to Buttigieg’s 18 percent and Klobuchar’s 6 percent.

Finally, Sanders won a clear victory over Buttigieg, 35 percent to 23 percent, among the 38 percent of voters who said the most important quality in a candidate was their ability to “bring needed change.” However, the group of people who thought it was more important to unite the country (32 percent of the electorate) gave 31 percent of the vote each to Buttigieg and Klobuchar. (Sanders got just 9 percent of these voters.)

Geographically, Sanders won by racking up large vote margins in New Hampshire’s cities (just as he did in Iowa en route to winning the final-alignment popular vote there — but luckily for Sanders, New Hampshire doesn’t have “state delegate equivalents”). Sanders won New Hampshire’s six largest municipalities — Manchester, Nashua, Concord, Derry, Dover and Rochester.

By contrast, a map of the results shows Buttigieg had pockets of support in the rural, conservative Lakes Region and especially in the far-flung Boston suburbs in the southeastern corner of the state. These heavily white towns have high median incomes, high educational attainment and a strong Republican lean in general elections, making them good fits for Buttigieg and his message of reaching across the aisle.

But even in those spots, Buttigieg was likely again held back by Klobuchar. According to the exit polls, Klobuchar and Buttigieg were the two top choices of college-educated white voters, at 26 percent and 24 percent support. It seems likely that, if Klobuchar hadn’t been in the race, many of her votes in highly educated communities would have gone to Buttigieg (or vice versa). Given that Buttigieg lost to Sanders statewide by only about 4,000 votes, it’s quite possible that Sanders only won because the Buttigieg/Klobuchar vote was split.

The final notable result from New Hampshire had nothing to do with the candidates at all: It was the more than 283,000 people who cast a ballot in the Democratic primary. Results are still coming in, but the number is close to the all-time turnout record for any one party in a New Hampshire primary (288,672 in the 2008 Democratic primary). However, that number is less impressive once you factor in the fact that New Hampshire has roughly 89,000 more eligible voters in 2020 than it did in 2008, according to estimates by University of Florida professor Michael McDonald. As a percentage of eligible voters, turnout in the Democratic primary this year was around 26 percent, while it was 29 percent in the 2008 Democratic primary.

Laura Bronner contributed research.