Earlier I wrote that although more Republican women are running, the GOP conference is still largely represented by men. North Carolina, where polls just closed, nicely illustrates some of the reasons that Republican women continue to trail Democratic women by such large margins, in Congress. North Carolina has low female representation in their state legislature (which is just 29 percent female), and that limits their recruitment from that pool. And in today's open primaries in safely Republican districts where the GOP primary will effectively decide the next representative, women aren't among the most competitive. As Kaleigh wrote earlier, in the 8th District outside Charlotte, the two GOP front runners are state Rep. John Bradford, and Baptist minister Mark Harris. And in the 10th District, the race is largely between state Rep. Grey Mills and Pat Harrigan, a gun manufacturer. There are several non-incumbent women running in the state today, but none of the groups we are watching that support Republican women (Winning for Women, VIEW-PAC, E-PAC or Maggie's List) have made endorsements.

—Meredith Conroy, 538 contributor

ABC News projects that Trump will win Virginia's Republican presidential primary. We'll have to wait to see how the final totals break down, but this isn't much of a surprise considering Trump had comfortably led most polling of the GOP race in the Old Dominion. Now, Virginia's more highly-educated population and Trump's weaker performance there in 2016 probably makes it one of Haley's better states tonight. Yet the fact the result there has already been projected less than a half hour after polls closed may foreshadow a Trump sweep tonight. Loudoun County's early returns demonstrate how Haley is coming up short: Sitting outside of Washington, D.C., in vote-rich northern Virginia, Loudoun is a Democratic-leaning and highly affluent county — the kind of place Haley has done better in. But she's still trailing Trump there by around 6 percentage points, 52 percent to 46 percent, with one-third of the expected vote reporting.

—Geoffrey Skelley, 538

While we wait for polls to close and results to come in, I'll muse about the bigger picture here. Depending on how things go, this might be the end of Haley's candidacy. But either way, we should think about what's at stake in the contest between her and Trump. Broadly speaking, she has increasingly presented herself as the Trump/MAGA alternative. In some ways, she's made this distinction clear, most recently by suggesting she might not stick with her pledge to support the party nominee, and denouncing his actions on Jan. 6, 2021.

But the rest of her candidacy has been mostly about other stuff — how she'd be more competitive against Biden, and about giving voters a choice in the primary. On one of the main issues that set Trump apart from the rest of the GOP field in 2016, immigration, Haley has also been very conservative, signing one of the toughest state bills when she was governor of South Carolina and adopting Trump's language about toughness at the border. As in 2016, Trump seems poised to soundly defeat his primary rivals. But in terms of the real GOP alternatives to Trumpism, it's definitely not 2016 anymore.

—Julia Azari, 538 contributor

The main concerns about the top candidates didn’t resonate with primary voters in North Carolina. Seventy-five percent of likely North Carolina Republican primary voters said that Trump’s criminal indictments were not a serious consideration for them, according to a February poll by Emerson College/The Hill, while 25 percent said the indictments raised “serious doubts” in their minds about voting for Trump. Democratic primary voters in the state were more worried about Biden’s age than Republican primary voters were about Trump’s indictments: 34 percent of likely Democratic primary voters said Biden’s age raised serious doubts about voting for him, while 66 percent said it was not a consideration.

—Mary Radcliffe, 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