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. 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 and earned 122 delegates, needs 1,093 more to hit his so-called "magic number" of 1,215. Once he receives that many delegates, 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, though that could change depending on how many delegates he receives on Super Tuesday and in the days leading up to it. The exact number of delegates available on a date can also change as state parties finalize their plans.

Former UN Ambassador Nikki Haley, the last major candidate on the Republican side, enters this week having won a fraction of delegates available in four of the six states and territories that have awarded them thus far.

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.