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

Big picture, this was a good night for Trump, who gets another win under his belt, avoids the embarrassment of losing an early state, and gets to compete in much more favorable territory from now on. It's obvious he's going to be the Republican nominee for president. But I don't think we should lose sight of the fact that just under half of Republican primary voters in the first two states voted for someone other than Trump, even as his inevitability has become apparent. I do think that should be a cause for some concern among Republicans moving forward, given that the general election will likely be brutally close and even a small drop in Republican support for Trump could prove fatal. The longer Haley stays in, the more data we'll get on just how many GOP voters there are who are not entirely on board with Trump, especially as she steps up her direct attacks on him. There's been so much conversation about Biden's struggles within the Democratic coalition — which are real and worthy of attention — but Trump may face similar challenges as the nominee as well.

—Jacob Rubashkin, Inside Elections