Super Tuesday: What you should know ahead of the upcoming U.S. primaries

The earliest Donald Trump can hit the number of delegates needed to clinch his party's nomination is March 12, while for Joe Biden it's March 19.

More than one-third of the total delegates available in both the Republican and Democratic presidential primaries will be awarded on Super Tuesday, when 16 states and one U.S. territory hold presidential nominating contests.

On the Republican side, 854 of 2,429 will be at stake on Super Tuesday, which is traditionally the biggest day on the presidential primary calendar when it comes to the number of states holding presidential primaries and caucuses, as well as the number of delegates in play. Democrats will award 1,420 delegates, also more than one-third of those at stake in all. Nobody will lock up the nomination on Super Tuesday, but each party’s frontrunner can get pretty close.

Former President Donald Trump, who has won every presidential contest in which he’s appeared on the ballot — except for the District of Columbia — and earned 122 delegates, needs 971 more to hit his “magic number” of 1,215. Once he receives that many, he’ll have won a majority of available delegates to the Republican convention this summer and will be considered the party’s presumptive nominee.

The earliest Trump can hit that number is March 12. Trump currently has 244 delegates after additional wins over the weekend in Michigan, Missouri and Idaho. Though former U.N. Ambassador Nikki Haley, the last major candidate on the Republican side, won all 19 delegates in the District of Columbia’s primary, Trump could clinch the nomination by winning about 90% of the remaining delegates at stake from now through March 12.

Republican delegate rules vary by state, but their system generally makes it easier for frontrunners to quickly rack up large numbers of delegates because many states — including Super Tuesday’s biggest prize, California — award all their delegates to candidates who win a majority of the vote. In Texas, which has the second biggest delegate haul, 150 delegates will be assigned based on the Super Tuesday primary results, while state officials say they will assign another 11 at the statewide convention in May. The exact number of delegates available on a date can also change as state parties finalize their plans.

On the Democratic side, President Joe Biden is in a position to pick up a substantial number of delegates. Biden’s magic number currently sits at 1,968, though that could shift slightly depending on how the party decides to handle New Hampshire, which broke party rules by holding its party primary in January. The earliest Biden can hit that figure is March 19. He currently has 206 delegates.

Democrats award delegates proportionally everywhere, making it easier for trailing candidates to pick up delegates, at least in theory. Biden’s closest challenger, Rep. Dean Phillips, hasn’t been able to take advantage, but these rules open the door for ballot options like “uncommitted” or “no preference” to receive delegates, should they qualify by meeting a vote threshold of 15%, either statewide or in a congressional district.

These uncommitted delegates, who will arrive at the Democrats’ summer convention unpledged and can choose whom to vote for, have been the only thing between Biden and a clean sweep thus far. In Michigan, the “uncommitted” ballot option received two delegates. Seven Super Tuesday states – including Iowa, whose all-mail election will report results that day – offer some sort of “uncommitted” option on their Democratic ballots.