As Nathaniel and I discussed earlier, dynamics in the Texas state legislative elections have been particularly contentious this year, with the governor and Trump endorsing at least eight challengers to Republican incumbents in the state House. As of now, seven of those challengers are currently leading their primaries, though a few look headed to a runoff. One challenger, Barry Wernick in the 108th, is trailing by just 2 points.

—Mary Radcliffe, 538

ABC News projects that Biden will win the Minnesota Democratic primary, and Trump will win the Republican primary. Biden’s win is expected, but also salt in the wound for his highest-profile competitor, Minnesota Rep. Dean Phillips, who gave up a safe seat in Congress and the potential for a strong statewide run in a few years to launch his no-shot challenge against Biden.

—Jacob Rubashkin, Inside Elections

ABC News projects that Trump will win the Massachusetts primary, his 10th win of the evening. With 15 percent of the expected vote reporting, Trump is leading Haley in the Bay State 59 percent to 37 percent. Yet again, this is another state where Haley was hoping to do well: Massachusetts has a lot of college graduates, and it allows independents and Democrats to vote in the Republican primary. But with Trump’s win, the Haley campaign turns its lonely eyes to Vermont.

—Nathaniel Rakich, 538

With 56 percent of the expected vote now reporting, Trump has opened up a bit of a lead against Haley in Vermont. He has half the vote, and Haley is just behind him with 47 percent. Still, that's closer than the two polls, had us expecting. There's still room for Haley to pull out a win, which she would need: all of the state's 17 primary delegates go to the winner. That is, unless they both end up with under 50 percent of the vote, in which case they split the delegates proportionally.

—Monica Potts, 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