Super Tuesday primaries 2024: Trump and Biden dominate, Haley drops out

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.


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Trump projected to win Colorado

ABC News can now project that Trump will win the Colorado primary. With almost half the expected vote reporting already, Trump has 60 percent to Haley's 36 percent. It's Trump's eighth win of the evening already, and this one is particularly rough for Haley, as this was one of the few states where she had the best shot at an upset win.

—Nathaniel Rakich, 538


Will Minnesota be nice for Trump?

Polls have now closed in Minnesota, which was a sleeper battleground in the 2016 general election, but tends to support Democrats. There are a greater-than-average number of college graduates in the state, which should be good for Haley, but there's also a sizable white working class population, which, if you're reading this live blog, you probably already know, is good news for Trump.

—Jacob Rubashkin, Inside Elections


Trump projected to win Alabama

In one of the least surprising developments of the night, ABC News projects that Trump will win Alabama. Only 5 percent of the expected vote has reported there, but Trump leads Haley by a punishing 69-point margin, 83 percent to 14 percent. We expected Alabama to be one of Trump's strongest states, and that looks to be the case.

—Geoffrey Skelley, 538


Our first glimpse at Colorado

Going into tonight, I thought that Colorado could be a dark horse state for Haley. There wasn't a single poll of the race there, and the state's highly educated demographics seemed like a good fit for her.

Well, so far, it ain't happening. With 28 percent of the expected vote reporting, Trump is taking 57 percent of the vote there, while Haley has just 40 percent.

—Nathaniel Rakich, 538


More thoughts on primary polls

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