Nathaniel just mentioned Nikki Haley's strength in the well-educated, affluent communities around Boston. If you want to learn more about that group, its connection to the defense industry, its ambivalent views on racial integration, and its long-term movement into the Democratic coalition, check out historian Lily Geismer's book "Don't Blame Us".

—Dan Hopkins, 538 contributor

Trump is speaking now (right on schedule, for once!) and it's one of those "pivot to the general" speeches candidates give once they win the nomination. But it's also like he's playing his greatest hits on 1.5x speed: In the last five minutes, he has talked about immigration (saying migrants are coming in on airplanes), ISIS (he says he wiped them out in four weeks), inflation (chastising "Bidenomics") and energy generation, and he attacked Biden for his age (at one point claiming that the president cannot lift a beach chair which "weighs nine ounces").

One thing missing? Any mention of Haley. Remember, Trump is not technically the nominee until the convention says so, and he's not the presumptive nominee until he wins enough delegates. He is having a super Super Tuesday tonight, but he's not quite there ... yet.

—G. Elliott Morris, 538

Dean Phillips's tepid campaign may not last until the morning. Phillips has previously stated that he would drop out and endorse the likely Democratic nominee if his campaign wasn't viable after Super Tuesday. So far, his highest level of support tonight is in Oklahoma, where he's currently pulling 9 percent of the Democratic primary vote. That's closely followed by his home state of Minnesota, where he's winning a similar level of support. But at least he can say he won something today: tiny Cimarron County in the Oklahoma panhandle, where he currently leads Biden by five votes out of 21 total that were cast.

—Cooper Burton, 538

Trump is winning Massachusetts 61 percent to 36 percent, but as you can see in the map below, Haley is winning Boston and many of its well-to-do western suburbs like Concord, Wellesley and Weston. While these towns are now solidly Democratic, they are also home to a lot of the fiscally conservative, socially liberal voters who have supported moderate Republicans for governor like Mitt Romney and Charlie Baker. It’s basically the exact kind of well-educated voter that hates Trump but misses the old Republican Party, which Haley has become an avatar for.

—Nathaniel Rakich, 538

It has become somewhat of a theme of our live blogs this primary calendar to note that Trump's challengers are beating their polls. This first looked to be the case in New Hampshire, where polls significantly underestimate support among Republican likely voters for Haley. But the pattern is more robust than one state: In fact Haley has been beating her polls by an average of five points (in vote share) once you account for undecided voters in these surveys. The consistency of this pattern is striking enough to warrant a post on the matter.

As Mary said earlier, polling primaries is hard! That is betrayed by the fact that POTUS primary polls are by far the least accurate type of poll in 538's pollster rating database going back to 1999. But error is different than bias, and when most of the polls are off in the same direction, something has gone awry.

That "something" is likely the difficulty in obtaining opinions of moderate Republicans from samples of "likely Republican primary voters." Remember that fewer than one percent of people called for a poll actually complete the interview. That means the ones that do are statistical "weirdos" (excuse the technical language). Pollsters adjust for this by weighting their samples to known population benchmarks — like the percent of all adults who are white, over 65, have a college education etc. But in primaries, such benchmarks do not actually exist; pollsters are just making educated guesses about them.

My theory is that most of these primary polls pulling samples of voters from voter registration lists are missing moderate crossover partisans and first-time voters. Additionally, we know that people who are highly motivated to participate in polls (the "weirdos") also happen to be the most politically and ideologically extreme Americans. That's a recipe for polling bias in primaries, where weighting to party, past vote and polarized demographic benchmarks does not control for the partisan consequences of overrepresenting politically engaged Americans.

Now, none of this is to say that polling is "broken." It's just hard to precisely sample a population that doesn't really exist. The polls for the 2024 primary still have below-average error, historically speaking, so we shouldn't go throwing out the baby with the bathwater. But this could nevertheless be a sign of pollsters having a hard time reaching moderate "normie" voters. And if that persists, it could have consequences for general election polls too.

—G. Elliott Morris, 538