Overnight last night, ABC News projected that firearms manufacturer Pat Harrigan will be the GOP nominee in North Carolina's 10th District. He defeated more conservative Republican Grey Mills 41 percent to 39 percent. The 10th District is a solidly red seat currently represented by retiring Rep. Patrick McHenry, and Harrigan should have no trouble winning it in the fall.

—Nathaniel Rakich, 538

Last night, the "uncommitted" campaign made headway in a few more states. After a protest vote for Biden's response to Israel's war against Gaza helped net over 100,000 uncommitted votes in last week's Michigan Democratic primary, supporters of the Listen to Michigan campaign expanded their efforts to other states with "uncommitted" or similar language as an option on primary ballots.

With 89 percent of the expected vote reporting, 19 percent of Democratic primary voters in Minnesota voted uncommitted, eclipsing the 13 percent reached last week in Michigan. That means "uncommitted" will send at least 8 (and up to 11) delegates from Minnesota to the Democratic National Convention in August, per the latest ABC News projections.

"No preference" also garnered 13 percent of ballots cast in North Carolina and 9 percent in Massachusetts, while 8 percent of primary voters in Colorado chose "noncommitted." However, those aren't enough to meet their respective states' thresholds to send a delegate to the national convention. (That's 15 percent in all three of those states.)

—Irena Li, 538

While Haley called on Trump to earn Republicans' votes, Mitch McConnell suggested that he already has. "It is abundantly clear that former President Trump has earned the requisite support of Republican voters to be our nominee for President of the United States," McConnell said in a statement. The rest was pretty standard endorsement fare, going on to tout Trump's accomplishments on tax reform and judicial appointments, and criticizing Biden.

It's an undramatic end to the minor drama over whether the soon-departing majority leader would endorse Trump, with whom he's undoubtedly had a rocky relationship. In the end, McConnell waited until just after Trump's final major opponent dropped out to fall in line. With one of the last major (potential) party holdouts in his corner, the general election train is in full swing for Trump.

—Tia Yang, 538

According to the latest numbers from our colleagues at ABC News, Trump has 1,051 of the 1,215 delegates he needs to mathematically clinch the Republican nomination for president. Haley's withdrawal from the race puts him on track to reach that magic number next Tuesday, March 12. A total of 199 delegates will be allocated between now and then, and presumably Trump will win all or almost all of them.

—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