538 tracked how Trump and Haley did, plus key U.S. House and Senate races.
March 5 was Super Tuesday — the biggest election day of the year until the one in November! With former President Donald Trump projected to win 14 of the day's 15 GOP presidential nominating contests, former U.N. Ambassador Nikki Haley announced Wednesday morning that she is suspending her campaign.
It was also the first downballot primary day of 2024, with important contests for Senate, House and governor in states like Alabama, California, North Carolina and Texas.
538 reporters, analysts and contributors broke down the election results as they came in with live updates, analysis and commentary. Read our full live blog below.
In 2016, people who said they were undecided in polls were more likely to vote for Trump as "professor polls" explains in this great 538 video I show my students. But in 2024, Trump supporters aren't so shy. It's the rest of the GOP that might be more bashful.
—Meredith Conroy, 538 contributor
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
