I've already gone on about Phillips a bit tonight, but I think it's interesting that he tried to challenge Biden from the center, or mostly on the basis of personal characteristics. This feels notable because Biden's major weakness would seem to be from the left. But the main vehicle for opposition votes to Biden has been the "uncommitted" movement — not a specific candidate. This might be because the progressive wing of the party doesn't have a younger and agreed-upon candidate yet, or because they see Biden as the best realistic bet for achieving some of their policy goals.

—Julia Azari, 538 contributor

As Monica just noted, about the only drama in the presidential primary contests tonight can be found in Vermont, where Haley actually might defeat Trump in a traditional, state-run primary (unlike the party-run primary she won in Washington, D.C., over the weekend).

So, what's going on in Vermont? Fundamentally, the Republican primary electorate just isn't as conservative in Vermont. I've been using the 2016 Republican nomination race as a back-of-the-napkin guide to the makeup of the GOP electorate this year, and it's been useful. At this point, we could split the GOP into two parts: those who voted for Trump, Ted Cruz and Ben Carson, who tend to make up the Trumpier part of the GOP now; and those who backed Marco Rubio and John Kasich, who aren't as inclined to back Trump. Looking at how the Super Tuesday states voted in 2016, you'll notice that Vermont is the only state voting today in which the combined vote share for Rubio and Kasich outdistanced the Trump, Cruz and Carson cohort.

Back in 2016, the types of voters who backed Rubio and Kasich tended to be more moderate and more likely to hold a four-year college degree. In that sense, they attracted parts of the GOP coalition (and beyond) that make up much of Haley's coalition this year. As we already discussed, some Democratic-leaning voters may have helped Haley in every contest, and Vermont happens to also be a very blue state full of those voters.

—Geoffrey Skelley, 538

With Texas Republican Sen. Ted Cruz projected to win his primary — he's got 89 percent of the votes counted so far — the question becomes whether he will face as tough a race in November as he did back in 2018. Six years ago, he beat Beto O'Rourke by just 2.6 percentage points, raising questions about whether Democrats could actually win a statewide federal race in the Lone Star State. But recently, his approval rating has notched up after being underwater for much of 2021 and 2022. On the Democratic side, Colin Allred is winning 62 percent of the Democratic vote with just over half the expected vote in.

—Dan Hopkins, 538 Contributor

In the Democratic primary for the Texas’s 15th Congressional District, Michelle Vallejo is leading with 32 percent of the expected vote in. She ran unsuccessfully for the seat in the 2022 midterms, but she’s leading her opponent, John Villarreal Rigney, 73 percent to 27 percent, according to The New York Times. Villarreal Rigney tried to run as the more conservative candidate, but Vallejo has the endorsement of much of the Democratic establishment and the pro-Israel group, Democratic Majority for Israel, or DMFI. AIPAC has endorsed her Republican opponent, the current incumbent, Rep. Monica de la Cruz. If Democrats can flip any seat in Texas, this is a likely one, making this race potentially competitive in November. Both AIPAC and DMFI have invested on the Democratic side to try to fend of progressive, anti-war challengers in Congress.

—Monica Potts, 538

In several of California's open congressional districts, tonight could be the end of any suspense about who the next representative will be. Or, it could be the start of an eight-month intraparty slog.

That's because California's unique all-party primary system — where the top two primary vote-getters advance to the general election — allows for either a traditional contest between a Democrat and a Republican or a fight between members of the same party in the general election, and it's not always obvious which one you're going to get. That's the case in at least four open-seat races today — three Democratic and one Republican.

In California's 16th District, there are nine Democrats but just two Republicans vying to replace Democratic Rep. Anna Eshoo. While limited polling of the district suggests that former San Jose Mayor Sam Liccardo or Santa Clara Supervisor Joe Simitian, both Democrats, are the front-runners, if one of the two Republicans consolidates most of the GOP vote and the Democratic vote scatters among the many candidates, a Republican could finish in the top two. In the 2022 primary, the Republican candidates didn't meet that threshold, splitting a combined 22 percent of the vote; the four GOP candidates in the state's Senate race won a combined 24 percent in the district. A Republican advancing would ensure that whichever Democrat also finished ahead would win the general election in November, given the district's partisan bent. But if two Democrats finish in the top two, it'll be a real race.

Same goes in the 30th District, where Adam Schiff is leaving to run for Senate. Twelve Democrats and just two Republicans will appear on the ballot there. In the 2022 primary, four GOP House candidates totaled 21 percent, and Senate GOP candidates combined for a smaller 22 percent. Democratic state legislators Anthony Portantino and Laura Friedman, and Democratic former city attorney Mike Feuer are the front-runners for this seat; if two of those three make it to the general election, it will be an expensive and sharp-elbowed race to November, but if one of the Republicans squeezes in, it's basically over.

In the 31st District, where Democrat Grace Napolitano is retiring, six Democrats and two Republicans are running. In 2022, the one Republican running for the seat, Daniel Martinez, advanced to the general by winning 37 percent of the vote in the primary. Former Rep. Gil Cisneros, state Sens. Susan Rubio and Bob Archuleta, former Monrovia Mayor Mary Ann Lutz and attorney Greg Hafif are all running well-funded Democratic campaigns, creating the possibility that Martinez, who is running again, could finish in the top two instead of two Democrats, effectively ending this race tonight.

And in Kevin McCarthy's old seat, the 20th District, it's a similar story with the parties reversed. There, the two Democrats will probably combine for around 30 percent of the primary vote (in 2022, the House candidates combined for 30 percent and the Senate candidates for 32 percent), while six Republicans fight over the remaining 70 percent (a seventh dropped out but remains on the ballot).

—Jacob Rubashkin, Inside Elections