Haley is now speaking live from Charleston, South Carolina, and she just announced she is suspending her campaign. There are now no major Republican candidates left running against Trump.

—Nathaniel Rakich, 538

While you were sleeping, ABC News projected Trump as the winner in the last two presidential contests: Alaska and Utah. Trump currently leads in Alaska 88 percent to 12 percent and in Utah 57 percent to 42 percent.

—Nathaniel Rakich, 538

After a full-ish night's sleep, we're back on the live blog as the winners of several House primaries from Super Tuesday remain unknown. However, the big news this morning is that campaign sources are telling ABC News that Haley will suspend her campaign for president after winning just one primary yesterday, making Trump the presumptive Republican nominee. She will deliver remarks at 10 a.m. Eastern, and we'll cover it live right here.

—Nathaniel Rakich, 538

It's just past 2 a.m., and we've got major results in from most of Super Tuesday's wide-ranging slate of primary contests. So far, Trump has won at least 12 of the 15 states holding GOP presidential nominating contests, while Haley has won Vermont — though whether she hits a 50 percent (plus one vote) threshold of victory there will determine the exact number of delegates she takes home.

Either way, with an estimated 943 total delegates to Haley's 86 so far, per ABC News projections, Trump's well on his way to securing the magic delegate majority number of 1,215 — though it will take at least another week. He's so far secured 667 delegates tonight and is likely to hit the 769 mark that Elliott noted earlier would set him up to mathematically clinch the nomination on March 12. Of course, we're all watching to see if Haley drops out sooner.

In other highlights:

- As expected, Republican Lt. Gov. Mark Robinson and Democratic state Attorney General Josh Stein secured their parties' respective nominations, and will go head to head in what's expected to be a close general election contest for governor.

- Rep. Colin Allred locked up the Democratic nomination in Texas's Senate race, and will face off against Sen. Ted Cruz in the general.

- Democratic Rep. Adam Schiff secured not only the top spot in a top-two primary, but also a likely glide path to the nomination, as the second spot on November's ballot went to Republican Steve Garvey instead of a second Democrat.

We're still tracking a dozen-odd downballot races that have yet to be projected, and awaiting presidential primary results in Utah and Alaska, so we'll see you back here tomorrow ... er, later today, with more results and analysis!

—Tia Yang, 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