A Beginner’s Guide to Super Tuesday

Super Tuesday, traditionally one of the most important dates on the U.S. political calendar, is fast approaching — though we can’t blame you if it feels a little anticlimactic this year, with both President Biden and former President Donald J. Trump doing their best to skip ahead to the general election.

Here’s what you need to know.

What is Super Tuesday?

It is the day in the presidential primary cycle when the most states vote. The exact number varies by year, but it is common for a third of all delegates to the Republican or Democratic conventions to be awarded on Super Tuesday.

This year, it will account for 874 of 2,429 Republican delegates, or 36 percent. By the time Super Tuesday is over, 1,151 of the total will have been allocated this primary season. The New York Times is tracking the Republican delegate count here.

When is Super Tuesday?

This year, it is Tuesday, March 5.

Super Tuesday is occasionally in February but usually in March. Because it is one of the first primary days after those in the designated early-voting states, such as Iowa and New Hampshire, its timing depends on the timing of those states.

Which states will be voting?

This year, 15 states will vote on Super Tuesday: Alabama, Alaska, Arkansas, California, Colorado, Maine, Massachusetts, Minnesota, North Carolina, Oklahoma, Tennessee, Texas, Utah, Vermont and Virginia. One territory, American Samoa, will also vote.

We will also learn the results of the Democratic contest in Iowa, which is being held by mail over several weeks. (Iowa Republicans held their caucuses in mid-January.)

How important will it be this year?

That depends on how Nikki Haley does in South Carolina on Feb. 24 and in Michigan on Feb. 27.

If Ms. Haley wins, or comes very close to winning, one or both of those states, Super Tuesday will be crucial in demonstrating whether she can remain competitive with Mr. Trump on a national scale. Most of the states that will vote on Super Tuesday allow unaffiliated voters to participate in primaries, so there are at least theoretical opportunities for her to recreate the coalition that got her over 40 percent in New Hampshire.

But if she loses decisively in South Carolina and Michigan, Mr. Trump will have run the board in the early-voting states. In that case, it will be hard for Ms. Haley to argue that her candidacy is viable, and Mr. Trump could have the nomination pretty well wrapped up before Super Tuesday. He technically would not have the delegates needed to clinch the nomination, but no serious competitors would be left, and the remaining votes would be academic.

On the Democratic side, nothing indicates that the race is competitive. That is normal for the party whose main candidate is an incumbent running for re-election.

What is the history of Super Tuesday?

The term “Super Tuesday” has existed since the 1970s, but in its early days it was sometimes used to refer to the last big collection of primaries, not the first, according to the National Constitution Center. Its modern usage was cemented in the 1980s, as states moved their primaries earlier on the calendar to try to increase their influence.

The shift was driven by Southern states that — after the landslide general-election loss of the liberal Walter Mondale in 1984 — wanted to have their say early enough in the process to push the Democratic Party toward a more conservative nominee in 1988.

It did not work. Senator Al Gore of Tennessee split the Super Tuesday states with the Rev. Jesse Jackson, and Gov. Michael Dukakis of Massachusetts won the party’s nomination.

But that result ended up being an exception. More often than not, since 1988, in both parties, a clear front-runner has emerged from Super Tuesday and become the nominee.