As Dan mentioned earlier, the pre-election polls in both Iowa and New Hampshire didn’t seem to be missing Trump voters. But if Biden stays at 67 percent, as Nathaniel observed, it looks like polls of the Democratic primary in New Hampshire might have understated Biden’s support by quite a bit.

—Mary Radcliffe, 538

Edison Research, from which we get our election results, is separating out write-in votes for Biden in the Democratic primary. And with 17 percent of the expected vote reporting, Biden write-ins account for 67 percent of the vote. Phillips is pulling 20 percent, other write-ins are taking 6 percent and Williamson is getting 4 percent.

—Nathaniel Rakich, 538

Geoffrey, I wonder if Nevada will factor into Haley’s decision about whether to drop out. If she does get some favorable media attention from winning the primary, maybe that will improve her standing in South Carolina. Alternatively, if “none of the above” embarrasses her, maybe she’ll drop out.

—Nathaniel Rakich, 538

Haley focused her speech on South Carolina's Feb. 24 primary. But that's not technically the next contest in the Republican presidential primary. The next Republican electoral event is actually Nevada's GOP primary on Feb. 6. However, the Nevada GOP opted against using the state-run primary and instead will use caucuses on Feb. 8 to allocate delegates to candidates. As a result, the Nevada primary is a kind of "beauty contest" — a vote with no bearing on delegate allocation.

But it gets a bit stranger from there. As part of the filing rules for the caucuses, the Nevada GOP required candidates to not enter the primary taking place two days earlier. Some candidates, including Trump, didn't file for the primary. But Haley, perhaps thinking Trump winning the caucuses was a sure thing, filed for the primary and not the caucuses. So now Haley is essentially unopposed in the primary — there are a few minor candidates and drop-outs like Tim Scott and Mike Pence — and Trump is unopposed in the caucuses. Will Haley be able to play up a win in Nevada? Unclear.

But it's also possible that pro-Trump Republicans could make a concerted effort to take advantage of Nevada's unusual "none of these candidates" ballot option. Encouraging Trump voters to cast a vote for none of the above could keep Haley from winning with a majority, should enough choose it. All of this may feel about as crazy as putting your life's savings on black at the roulette table. However, state parties can opt against using a state-run primary to allocate their delegates and instead use a party-run event like a caucus — there are many examples throughout the history of presidential nomination contests. It's just not usually something that happens in an early-voting state.

—Geoffrey Skelley, 538

It's been only eight days since Iowa's first-in-the-nation caucuses last Monday, but a lot has happened since then. On the night of the caucuses, businessman Vivek Ramaswamy dropped out of the race and endorsed former President Donald Trump, and Florida Gov. Ron DeSantis followed suit on Sunday. With former Arkansas Gov. Asa Hutchinson also leaving the race last week, former U.N. Ambassador Nikki Haley is Trump's last major competitor standing.

And everyone has their eyes on New Hampshire as potentially the only state where Trump has a realistic chance of losing. Haley has invested heavily in New Hampshire and has been suggesting since early December that today's race would be the start of a competitive two-person primary between her and Trump. She's got her two-person race, but whether it will be remotely competitive remains to be seen. Trump has only continued to consolidate party support since his Iowa victory, and anything less than a convincing win for him would be surprising.

So when might we know? First polls will close tonight at 7 p.m. Eastern, and last polls will close at 8 p.m., which is the earliest time we could have a race projection. But as we did last week (when Trump's victory was projected only 30 minutes after caucuses had begun), we will of course be sticking around no matter what happens to see how each candidate does across the state and discuss what it could mean for the rest of 2024.

And that's not all! Granite State Democrats also have a primary today, and it's a weird one — New Hampshire is violating Democratic primary calendar rules by holding it so early. As a result, President Joe Biden isn't campaigning or even on the ballot, but his competitors, Rep. Dean Phillips and self-help author Marianne Williamson, are. While Biden isn't expected to face serious competition for the actual nomination, his margin of victory today as a write-in candidate could be one early sign of Democrats' grassroots enthusiasm for the incumbent.

Bookmark this page for updates and analysis throughout the night!

—Tia Yang, 538