I just want to underscore Elliott's point about how hard polling has gotten with a quick story I wrote up in a paper with Tori Gorton called "On the Internet, No One Knows You're An Activist." We were trying to survey lower-engagement voters, so we drew a sample of 9,937 registered Pennsylvania voters who hadn't consistently voted 2012-2018. Then, we matched them to Facebook accounts and served ads to 1,321 inviting them to take a survey. 66 people clicked on our ad, 7 began the survey, 6 completed it, and 1 person left an email for follow-up. I of course want to express my deep gratitude to that one respondent. But beyond that, a 0.4% response rate magnifies sampling errors, because very small differences in people's willingness to take polls can add up to very large errors in vote margins. That's especially true in primaries, where pollsters can't use partisan identification to stabilize the results.

—Dan Hopkins, 538 contributor

We've been tracking Trump's non-incumbent endorsees (because endorsing the incumbent is kind of a gimme) tonight, and so far he's 4 for 4 of the races called. Addison McDowell, Trump's pick in North Carolina's GOP primary for the 6th District, is also leading. But in California, state Assemblyman Vince Fong, who received Trump's endorsement for the Republican primary in the state's 20th District (Kevin McCarthy's old seat), is trailing at 26 percent with 23 percent of the expected vote reporting.

—Kaleigh Rogers, 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

In California's 40th District, with 46 percent of the expected vote in according to the Associated Press, engineer Allyson Damikolas (endorsed by EMILY's List), is trailing former fire captain Joe Kerr (endorsed by the Congressional Progressive Caucus PAC). The 40th is a key target for Democrats, who are looking to win back some of the ground they gained (and then lost) in the Orange County area. The 40th District spans Riverside and San Bernardino Counties, too.

—Meredith Conroy, 538 contributor

Voters are choosing more than their parties' presidential nominees tonight. In five Super Tuesday states, they're also deciding on candidates for statewide and local offices. Several consequential judicial elections are being held tonight, for positions on state supreme courts in Alabama, Arkansas and Texas, and on the Criminal Court of Appeals in Texas.

In Arkansas, nonpartisan general elections are being held to fill two vacancies on the Supreme Court, creating a game of musical chairs among the sitting justices that could potentially accelerate the already-conservative court's rightward shift. Chief Justice Dan Kemp is stepping down, and three of the four candidates running to replace him are already sitting on the court, while another sitting justice is angling to move to a different open seat on the court. The shuffle could leave two vacancies that would allow conservative Gov. Sarah Huckabee Sanders to name replacements to finish their terms.

Alabama's Supreme Court Chief Justice Tom Parker, who recently made waves nationally with a ruling that frozen embryos used for IVF are children, is also retiring because of the state's mandatory retirement age. Two candidates are running for the Republican nomination to replace him: sitting Associate Justice Sarah Stewart (who had to give up her seat to run for the top slot) and former state Senator Bryan Taylor. While Stewart joined the 8-1 majority opinion in the IVF case and both candidates have defended the decision, Taylor has claimed that Stewart is the "most liberal" justice on the all-Republican court, and received a huge influx of outside spending from conservative anti-abortion group Fair Courts America. Whoever wins will likely face (and defeat) Democrat Greg Griffin>) in the general election.

In Texas, Supreme Court Justice John Devine is facing a primary challenger who has questioned his ethics, but a bigger political feud is playing out in other races. Allies of Republican Attorney General Ken Paxton are funding primary challengers to three Criminal Court of Appeals judges who ruled against him in a voter fraud decision, limiting his power to prosecute those cases. And as Nathaniel noted earlier, Paxton, who had been accused of abusing power to protect a political donor, has also endorsed primary challengers against 34 of the 60 Republican legislators who voted to impeach him last year.

—Monica Potts, 538