Okay, maybe I'm biased because it was my assignment to report out some of the downballot races tonight, but when the presidential primaries are basically all over but the cryin', they make for much more interesting politics. But once Biden and Trump make it official, don't let the intensity of the presidential race overshadow these races further down the ballot. There's a lot at stake — majority powers in two narrowly divided chambers! — and these races can sometimes tell us more about what voters think is important than the marquee race at the top of the ticket. Of course, you can always depend on 538 to keep you up to speed!

—Kaleigh Rogers, 538

With the exception of a remarkable outcome in American Samoa, this was a night without very many surprises. Trump and Biden continue to dominate their respective parties, even as doubts linger — about age, about policy and about electability, to name a few concerns. But Trump's main opponent, Haley, has just won her second primary of the season — Vermont. Biden has opposition on the left, but no challenger; from the center of his party, he has a challenger, but no clear opposition.

One lesson from all of this is that even for candidates with as many liabilities as these have, it is incredibly difficult to compete with the name recognition and influence of a sitting or former president. In theory, parties could opt to nominate someone other than the sitting president — in practice, they have not really done so since the mid-19th century. Parties have come to be defined by their presidents. We especially see this with Trump, but this primary season and Super Tuesday have highlighted just how much it's true of Biden, too.

And yet it shows the cracks in the presidential dominance of their parties as well. Even as Trump has largely taken over the GOP, there remains a consistent, if small, segment that would like to see the party move in a different direction. And even as Biden continues to (almost) sweep the primaries, activists are organizing to use the primaries to protest some of his policies. Still, it's telling that ultimately these intraparty disagreements aren't framed as fights between factions, but rather in terms of support or opposition to the presidential figure at the head of the party.

—Julia Azari, 538 contributor

We're not ending the live blog just yet since there are more results to come ... But we're going to get some shuteye and be back here tomorrow, bringing you updates from some of today's later-closing races.

So, it's "final" thoughts time — what did everyone take away from tonight's results?

—Tia Yang, 538

Interesting, Geoffrey. I was expecting Carl to win that one, as he had the geographic advantage: Carl and Moore were thrown together into this new district in redistricting, and Carl represented 59 percent of residents in the new district. But perhaps Moore’s conservative bona fides carried the day: He is a member of the House Freedom Caucus, so this primary was a victory for the insurgent wing of the Republican Party.

—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