ABC News projects that Rep. Barry Moore will defeat fellow Rep. Jerry Carl in Alabama's 1st District GOP primary, winning the lone incumbent-versus-incumbent primary we're expecting to have this cycle.

—Geoffrey Skelley, 538

The big races I was eyeing in North Carolina are tightening up. In the 1st District (which is set to be the only competitive Congressional race in the Tar Heel state in November), wealthy businesswoman Laurie Buckhout is projected to win the GOP nomination. The 6th District looks destined for a runoff. In the 8th District, Mark Harris (whose 2018 win was thrown out due to allegations of ballot fraud) is projected to win the Republican nomination. And in the 13th District, Kelly Daughtry, an attorney who came in third in the Republican primary in 2022, is creeping closer to the 30 percent threshold needed to avoid a runoff. Not a ton of surprises, but an interesting night downballot for sure!

—Kaleigh Rogers, 538

The race in California's 47th District is competitive within the Democratic field where, as we've mentioned, Rep. Katie Porter decided to run for Senate, opening up her House seat. The House primary she won in 2018 to face (and eventually defeat) the Republican incumbent, Mimi Walters was also competitive. In fact, Dave Min, who is running today, was the favored Democrat in that 2018 primary, but Porter beat him out to finish second, behind Walters, and went on to win the seat. With 46 percent of the expected vote in, Min is leading his closet rival, Joanna Weiss, by about 8 points.

—Meredith Conroy, 538 contributor

Redistricting made Alabama's 2nd District Democratic-leaning, and a bevy of candidates jumped into the party primary with a shot at winnable seat. But in Alabama, primary winners must win a majority, so the crowded race has made an April runoff likely. With about 80 percent of the expected vote reporting, former Justice Department official Shomari Figures leads with nearly 44 percent. ABC News has projected that Figures, the son of longtime state Sen. Vivian Figures and the late state Sen. Michael Figures, will advance to the likely runoff. The race of the second runoff spot is not set, but state House Minority Leader Anthony Daniels has 22 percent, ahead of state Rep. Napoleon Bracy's 16 percent. Daniel actually hails from Huntsville in the north of the state, far from the southern Alabama base of the district. Bracy is from Mobile, and there are still some votes left to report from there, so he can't be discounted.

—Geoffrey Skelley, 538

Super Tuesday has over 40 years of history that are deeply entwined with a bunch of issues in the presidential nomination process. The term "Super Tuesday" was first used in 1980 but was promoted by Democrats in 1988 as a deliberate effort to give an advantage to more moderate candidates. This was a direct reaction to the idea that the party's 1984 nominee, Walter Mondale, had lost to Ronald Reagan because he was too liberal. This strategy didn't really work out, though, and Democrats ended up nominating another northern liberal, Michael Dukakis.

In other words, this early attempt at a Super Tuesday brought some of the disadvantages of a regional primary, reducing the amount of attention on individual states and pressuring states to move their primaries earlier without really strengthening the influence of the region. Another drawback was that, by trying to enhance Southern influence by holding contests early, Super Tuesday also contributed to the "front-loading" problem", or the issue of having too many delegates selected at the beginning of the primary calendar.

Over time, Super Tuesday has taken on other significance as an important turning point in the race. As party politics scholar Caitlin Jewitt noted, in 2016, everyone thought that Sen. Ted Cruz needed to do well on Super Tuesday, which was heavily concentrated in Southern states where he needed to rack up wins — and when that didn't happen, it was a significant blow to his candidacy. For Biden in 2020, Super Tuesday marked the point when the party consolidated behind him. And in 2008, Super Tuesday made it clear that the Democratic nomination was a real race between Hillary Clinton and Barack Obama, as neither one scored a decisive victory.

It's hard to know exactly how this will play out in 2024. Republicans don't have the same ideological history with the big primary day as Democrats do. But the potential for a turning point in the race is there: Because so many delegates are at stake today, unless Haley wins a significant share of them, it may not make sense for her to stay in the race after tonight.

—Julia Azari, 538 contributor