As Super Tuesday votes are counted, the biggest question will be how many delegates each candidate won.
We probably won’t know the answer for some time.
Let’s walk through the night. The first polls close at 7 p.m. Eastern time in Vermont and Virginia, and we’ll start getting results soon afterward. We may know quickly who won those two states.
We should also learn relatively early which candidates won the three other states in the East: Maine, Massachusetts and North Carolina.
Polls will close by 9 p.m. in seven other states, including Colorado, Minnesota and Texas.
But the allocation of delegates to winning candidates takes more time.
And here’s the key: we won’t know how the night has gone overall until we get results from California, which has 415 delegates to distribute — more than 30 percent of what’s at stake Tuesday. The polls close there at 11 p.m. Eastern time, and it will take a long time to count all the votes.
After the 2018 election, it took nearly a month for the winner to be determined in the Central Valley congressional race between T.J. Cox, the Democrat, and David Valadao, the incumbent Republican. Mr. Valadao eventually conceded.
This time, California — like the other 13 states, American Samoa and Democrats Abroad voting on Tuesday — will have to figure out which candidates won enough votes to cross the 15 percent threshold to accrue delegates. And California will have to do those calculations both statewide and in each of its 53 congressional districts.
Of California’s 415 delegates, 144 will be allocated according to the statewide results — so whichever candidates win at least 15 percent of the vote will get a share of those delegates. The remaining 271 delegates will be divided among the congressional districts.
The more Democratic a congressional district is, the more delegates it has. California’s 12th and 13th districts — in San Francisco and Oakland — have seven delegates each, while the rest of the districts have four, five or six.
Here’s a cheat sheet for the night
Mr. Biden should do well in Virginia, North Carolina and Alabama, given his strong support among black voters, who make up a large share of the Democratic primary electorate in those states. Vermont and Maine ought to be friendly territory for Mr. Sanders.
If surprises happen — Mr. Sanders surging in the South, Mr. Biden doing better than expected in New England — it could alter expectations of how the night will go. Also watch to see if Senator Elizabeth Warren of Massachusetts, who was behind in the polls, starts hitting the 15 percent threshold in many places and picking up delegates.
We’ll also finally learn how much support former Mayor Michael R. Bloomberg has among voters. Tuesday is his first time on any ballot outside of New York City.
Because of Mr. Sanders’s strength in California — he has the largest team, has raised the most money and is the most popular among Latino voters — he is widely expected to win the most delegates on Super Tuesday. The issue is how big a lead he will have over his closest competitor — and how many rivals will reach the 15 percent threshold.
The delegate scenarios to watch for
Heading into Super Tuesday, Mr. Sanders led with 60 delegates to Mr. Biden’s 53.
There are 1,357 delegates at stake in Tuesday’s vote. If Mr. Sanders emerges with a lead of 250 delegates or more, he will be in great shape this spring to collect the outright majority of delegates required to clinch the Democratic nomination.
But if his lead is narrower, say 100 delegates, and Mr. Biden does well in the South and Texas, he will have a real shot at catching Mr. Sanders in the delegate race, given the makeup of the states to come. That could mean a long, bitter two-way battle.
Then there is a third possible scenario: If Ms. Warren and Mr. Bloomberg make the 15 percent threshold in more places than expected, they could limit the number of delegates that go to Mr. Sanders and Mr. Biden.
That would give political oxygen and momentum to two candidates who desperately need it and put the party on the path to a four-way fight to the July convention in Milwaukee.