In 2020, the general election polls missed Trump's support in key states, and the election came down to the wire. So far in 2024, though, polls don't seem to be understating Trump support. We'll see if that continues to hold.

—Dan Hopkins, 538 contributor

Something I’ve been turning over in my mind is whether Trump is more similar to an incumbent president seeking his party’s renomination, or to a candidate pursuing the nod in an open field. Trump has already been nominated twice by the GOP, and, obviously, occupied the White House for four years, making him perhaps one of the best-known people in the world. In that sense, he has a lot of the advantages of an incumbent. And it’s worth noting that some of the other presidents who have pursued non-consecutive terms, like Grover Cleveland and Theodore Roosevelt, also used the tools at their disposal — especially their ability to communicate with the public — to try to dominate their parties.

It matters for how we think about the eventual result. If Haley finishes with a strong second, that’s the kind of result that’s pointed to real vulnerability with past incumbents in New Hampshire. As Dan Hopkins pointed out earlier, competition in New Hampshire foreshadowed Lyndon B. Johnson’s decision not to run for reelection in 1968. George H.W. Bush was “jarred” in 1992 by Pat Buchanan taking 40 percent of the New Hampshire vote. And Gerald Ford had a narrow win over Ronald Reagan in 1976 in the vote totals, previewing not only a tough general election, but also brewing divisions in the GOP ranks.

This has implications for Biden as well, who is projected to win New Hampshire, despite not officially being on the ballot.

—Julia Azari, 538 contributor

DeSantis and Haley were vying to be the last opponent standing to Trump, and with DeSantis suspending his campaign over the weekend, Haley got her wish. An interesting side-effect is that we now have more of an ideological race. In a November 2023 survey, I found that Republicans evaluated Trump and DeSantis as similarly conservative. Haley, however, they saw as more moderate. So with DeSantis's departure, we have a clearer ideological divide.

—Dan Hopkins, 538 contributor

Trump tonight did something no Republican presidential candidate has done since President Ford in 1976: win both Iowa and New Hampshire in a contested primary. As I've been saying for a while, Trump is effectively the incumbent in this process — much in the same way that Ford was an incumbent with an asterisk in 1976. (He was the sitting president, but nobody had voted for him for anything.)

—Jacob Rubashkin, Inside Elections

Coming into today, a big question was whether independents would turn out a high level and put Haley in a competitive position versus Trump. Based on the preliminary exit poll, the answer was yes — but not enough for Haley to win. Overall, 45 percent of voters identified as independent or something else, and they went for Haley by 24 points, 61 percent to 37 percent. However, self-identified Republicans made up 4 percent of the electorate and. broke for Trump by 39 points, 74 percent to 25 percent. Even with a little help from the 6 percent who identified as Democrats (went for Haley 84 percent to 6 percent), Haley couldn't catch Trump because of his overwhelming edge among Republicans.

Another aspect of the independent question is New Hampshire's electoral access rules, which permit those not registered with a party — "undeclared" voters — to vote in party primaries. That group, which includes many self-identified independents, did turn out in a big way, making up 47 percent of the electorate to registered Republicans' 50 percent (same-day registrants made up the rest). And Haley won among undeclared voters 66 percent to 32 percent. But Trump won among registered Republicans 74 percent to 24 percent. These numbers will change somewhat after further weighting based on the results, but the big takeaway is that independents put Haley in range, but Trump's dominance among Republicans preserved his edge.

—Geoffrey Skelley, 538