I actually don't think polls are overestimating Trump by much, more that they're underestimating Haley. And I think it really comes down to undecided voters. Trump is a known quantity for pretty much everyone in America. So anyone who isn't sure if they're going to vote for him isn't unaware of his issues, but probably has some doubts about him. So my theory is that undecided voters skew, if not anti-Trump, at least Trump-skeptical and are disproportionately choosing Haley. You can see an inkling of that in the preliminary exit poll data: In Virginia, for example, voters that decided their vote choice earlier than this year went overwhelmingly for Trump (78 to 21 percent), but voters that made their decision later chose Haley (54 to 42 percent).

—Mary Radcliffe, 538

Polling nowadays is incredibly hard. Seeing response rates of under 2 percent is all too common. So even very slight differences in how fired up people are to take polls can translate into meaningful differences between polls and results. Primary polling is especially hard because you can't use partisan identification to benchmark how reasonable the sample looks. That all said, in New Hampshire and in South Carolina, I wonder if Haley may have benefited from the lack of a competitive Democratic primary, and the fact that some who might have otherwise voted in a Democratic primary were able to vote for Haley.

—Dan Hopkins, 538 contributor

What's everyone's favorite theory about why polls have seemed to consistently overestimate Trump support? (I know this was discussed some on the podcast.)

—Julia Azari, 538 contributor

Tonight I'll also be watching my home state of Arkansas, where polls just closed. There hasn't been recent polling on the GOP presidential primary there, but Trump remains popular in the conservative state, which he won 62 percent of the state in the 2020 general election. His former press secretary is the governor, Gov. Sarah Huckabee Sanders, and she endorsed him in the fall.

There's not much suspense downballot either. Rep. Steve Womack, who represents the northwest corner of the state—home to the University of Arkansas, Walmart, and other big businesses and booming towns—is fending off an unlikely challenger from his right and is the only Republican incumbent to face a challenger. That challenger, State Sen. Clint Penzo is against vaccines, the war in Ukraine, government spending and has criticized Womack's votes during the House speaker fight last fall. But Womack has represented the district for 13 years and all the advantages of incumbency.

On the Democratic side, all four candidates for the House are running uncontested.

Perhaps of a bit more interest — earlier, I wrote about the state Supreme Court races and how the outcomes there could result in a game of musical chairs leading the very conservative Sanders to make one or two appointments to the court.

—Monica Potts, 538

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