Beginning with the Iowa caucus in February 2020, the state-held primaries and caucuses will narrow down the slew of Democrats running for president until just one gains enough delegates to clinch the nomination.
Over 4,000 pledged and unpledged Democratic delegates are allocated among the states and territories based on factors like population, party members and the date of the state primary or caucus.
The Democratic Party applies uniform rules to all states for allocating delegates. In each state, delegates are allocated in proportion to the percentage of the primary or caucus vote in each district. But a candidate must win at least 15% of the vote to be allocated any delegates.
If a candidate drops out, each state reallocates delegates to the remaining candidates.
A candidate must receive 51% of the roughly 3,768 pledged delegates to become the party nominee. For Democrats, that is around 1,885 delegates.