Since the beginning of 2023, Republicans have spent nearly $78 million on advertising in New Hampshire, a sum that includes significant expenditures from candidates no longer in the race, such as Chris Christie and Tim Scott. As in Iowa, the top spender on TV in New Hampshire has been Stand for America, the Super PAC supporting Haley, which has run $23.5 million in advertising in the Granite State, according to AdImpact. No other candidate or group comes close to matching that number — the next-closest is Trump-supporting MAGA Inc., at $8.4 million. Haley herself has spent $5 million, while Trump has spent $7.4 million (candidates can buy ads on TV at a more favorable rate than outside groups).

You can see how big a priority New Hampshire has been for Haley and her allies, who began advertising in New Hampshire back in August. Just half of the pro-Haley spending in the state — $15.8 million of $31 million total between her campaign and supportive super PACs — has come within the last month of the race. Trump, meanwhile, is a relative newcomer to the airwaves. Of the $15.7 million in pro-Trump spending all cycle, almost all of it, $13.6 million, has come since Dec. 19, coinciding with Haley’s surge in the state’s polls.

A glance at TV spending also helps explain why DeSantis’s campaign floundered in New Hampshire, where the governor once polled as high as 25 percent but has fallen to less than 6 percent in the final 538 average before his exit from the race on Sunday. From an advertising perspective, DeSantis had effectively given up on the state in recent months. His Super PAC, the aptly named “Never Back Down,” spent $8 million in New Hampshire from April to November 2023, but hadn’t spent anything since.

—Jacob Rubashkin, Inside Elections

DeSantis was polling at only about 6 percent in New Hampshire when he dropped out of the race on Sunday, but 6 percent isn't nothing, and DeSantis's departure could help Trump on the margins tonight. According to an average of crosstabs from national primary polls, 48 percent of DeSantis supporters nationwide said that Trump was their second choice, while only 28 percent said Haley was. In New Hampshire, though, it was a little closer: 48 percent of DeSantis supporters there said Trump was their second choice, while 34 percent said Haley was.

If you take those numbers literally, we'd expect Trump to gain 3 points (48 percent of 6 percent) in New Hampshire from DeSantis's withdrawal, and Haley to gain 2 points (34 percent of 6 percent). However, DeSantis's endorsement of Trump on his way out of the race could mean Trump will gain even more ground. Overall, DeSantis's withdrawal is probably not good for Haley — although one New Hampshire poll, from Emerson College/WHDH-TV, did go against the grain and say that most DeSantis supporters would turn to Haley. These crosstabs all have very small sample sizes, and thus come with larger-than-usual margins of error, so we'll just have to see which of them is closest to the mark!

—Nathaniel Rakich, 538

In a January survey by Emerson College/WHDH-TV, just 52 percent of those who planned to vote in the New Hampshire Republican primary said they were registered as Republicans. Four percent said they were registered as Democrats, and 45 percent said they were registered as independents or with another party. (It’s worth noting that Democrats cannot vote in the Republican primary, so those 4 percent are going to be in for a disappointment when they show up to the polls.)

—Mary Radcliffe, 538

Although Iowa and New Hampshire both lead off the presidential nomination process and are both very white states, they have different-looking Republican electorates. Overall, New Hampshire GOP primary voters are less Republican, conservative and religious than Iowa Republican caucusgoers. This is due not only to differences across the two states' populations, but also divergent electoral rules that give New Hampshire a larger, less right-leaning electorate than Iowa. Thanks in part to these cleavages, the two states have voted for different winners in every open Republican presidential contest dating back to 1980.

One reason for these divergent results is that New Hampshire primary voters are less likely to identify as out-and-out Republicans than Iowa caucusgoers. Differing electoral rules help explain some of this contrast, as caucuses have lower participation rates than primaries. In Iowa, only registered members of a party may participate in that party's caucuses, and caucusgoers must attend these events at an appointed time on a weekday evening. By contrast, state-run primaries like New Hampshire's generally give voters roughly 12 hours to visit their regular polling place to cast a ballot, and they usually include at least a limited option to vote absentee. But critically, New Hampshire permits independent voters to participate in party primaries, unlike Iowa's caucuses and many other states' primaries.

New Hampshire Republican primary voters also tend to be less ideologically conservative than Iowa GOP caucusgoers. Once again, electoral rules play a role in this contrast. In part because of their higher barriers to participation, caucuses tend to attract the most committed and ideologically minded members of a party, whereas primaries attract a broader pool of voters, especially if independents are allowed to participate. Another reason for this ideological split is that New Hampshire's population has a smaller share of white evangelical Christians — a core part of the GOP base — than Iowa does. This is notable because white evangelical Christians are among the Americans most likely to identify as Republican, and they are more conservative than non-evangelical Republicans.

—Geoffrey Skelley, 538

New Hampshire is one of the least religious states in the country. That might help explain why Trump’s closest competitor, Haley, has closed in on his lead a bit there: He’s at 54 percent to her 36 percent. While in 2016, evangelical Christians and regular churchgoers were reluctant to throw their support behind Trump, this key Republican voting bloc is now his solid base. And they’re missing in this first-in-the-nation primary.

In Iowa last week, Trump improved on his 2016 caucuses performance by 35 points in the most evangelical areas of the state, according to a Washington Post analysis. That’s just the latest evidence that evangelical voters are his to lose. In the 2020 general election, he won 59 percent of voters who attend church at least monthly, according to a Pew Research Center analysis. More than that, Trump moved many of his voters to identify as evangelical Christian, regardless of their church attendance habits.

Evangelicals remain one of the most motivated, active parts of the Republican Party nationwide, and, without that, Trump’s campaign might be missing a little steam. In addition to being less religious, New Hampshire residents have other identity markers that pull them further from Trump’s base. It’s one of the most educated states in the country, and has had an active Libertarian Party. In this respect, New Hampshire Republicans are a bit different from their fellow party members in other states. All of these factors might be giving Haley a small opening, but Trump is still favored to win.

Looking beyond that toward November, New Hampshire has voted for the Democratic candidate in every election save one since 1992. So while the eventual Republican nominee will have a shot, the less religious nature of New Hampshire might be a sign that the state is simply becoming more solidly Democratic like its New England neighbors, at least when it comes to presidential elections.

—Monica Potts, 538