Thresholds for Democratic Party Delegate Allocation
Summary: Pledged delegates are proportionately allocated to candidates getting 15% or more in a primary or caucus. In such a large field, this may complicate the nominating process.
Each state (and territory) has a certain number of pledged delegates that are allocated based on the result of the vote in its Democratic primary or caucus. For those states with more than one congressional district, the available delegates are split - some are awarded based on the statewide (at-large) vote, while the remainder are based on the results in each individual congressional district*.
Pledged delegates are allocated in a proportional manner based on the vote share received by each candidate. This is at both the statewide and congressional district level.
There is a 15% minimum threshold to receive any delegates. Those not receiving the minimum are excluded, with the delegate pool divided proportionately among those candidates receiving 15% or more.
Implications for 2020
The Democratic nominating contest in 2016 was essentially between two candidates - Hillary Clinton and Bernie Sanders. The 2020 field is starting out much larger. Even if a few withdraw later this year, there will likely be 10+ candidates in the race when the Iowa caucuses kick off the nominating process on February 3rd. Given the more front-loaded 2020 calendar, this larger group is likely to be around for more events than would otherwise be the case.
The biggest potential implication of proportional allocation in such a large field is that no candidate arrives at the Milwaukee convention in July with enough delegates to win -- and a brokered convention results.
However, there are a couple issues at the state level that could also arise in these large field 2020 contests that weren't really mathematically possible in the two-person 2016 race
- No candidate receives 15% of the vote. If no candidate meets the 15% threshold, Democratic Party rules state the minimum to receive delegates will be 50% of the vote received by the front-runner. For example, if candidate A wins with 10% of the vote, delegates will be allocated proportionately to anyone that receives 5% or more.
- Only one candidate exceeds 15% of the vote -- but just barely. If only one candidate gets 15%, the allocation is effectively winner-take-all. This is not a big deal if that person is the clear frontrunner, getting 40%, 50% or more. However, what if the opposite is true -- a candidate wins with 16% vote share, while the next three candidates are just a few points behind. If that happened repeatedly favoring the same candidate, the party could potentially end up with a nominee that lacks broad support.
As we noted earlier, the threshold is determined at the individual congressional district level for district delegates and the state level for the statewide delegates. That in mind, these issues - to the extent they arise - may only affect a subset of a state's pledged delegates.
The above discussion is for pledged delegates only. Each state also has a certain number of automatic delegates, commonly referred to as unpledged or superdelegates. The role for superdelegates in 2020 will depend on how many pledged delegates the leader has after all primary and caucus events are completed. Here's an overview of how that will work.