Iowa is the first state to hold an electoral event for presidential nominations. A caucus is different than a primary election because Democrats will physically form presidential preference groups in their voting precinct. Another difference is that a candidate has to reach viability to be eligible for candidacy.
Once all participants arrive, preferential groups form. Viability is determined by the Number of Delegates in the precinct and the Total Number of Voters at the caucus.
If One Delegate is at Stake
* Largest group wins
If Two Delegates
* Total Voters divided by 4
If Three Delegates
* Total Voters divided by 6
Four or More Delegates
* Total Voters multiplied by 0.15 (15%)
Thirty minutes after initial groupings, voters can move to different groups.
Delegates = (# voters in preference group) / (# of voters present) * (# of delegates at stake)
* A group with viability is guaranteed at least one delegate.
* A viable group with a fraction ≥0.50 will gain an extra delegate.
* With unassigned delegate(s), the viable group(s) with the fraction closest to 0.50 will be awarded the extra delegate(s).
8 Delegates and 210 Voters
Viability: 210 × 0.15 = 31.5 → 32
Clinton 60
Edwards 25
Obama 80
Richardson 45
(# in Group)/210 * 8
Clinton 2.29
Edwards 0.95
Obama 3.04
Richardson 1.71
Edwards is not viable and Richardson gains an extra delegate (fraction ≥0.50). Clinton will receive the unassigned delegate over Obama (0.29 >0.04).
Both Obama and Richardson can donate voters to make Edwards viable. This would block Clinton’s extra delegate. Meanwhile, Clinton can ensure a third delegate by gaining six more voters and reaching a fraction ≥0.50.
Try this Caucus Calculator for different scenarios and strategy suggestions.