Instead of going to a poll and casting a vote like in a primary or a general election, Iowa Democrats gather registered voters at a specific time and location like a church or school. Then, the voters physically align in a room according to their voting preferences. More on that later!
Iowa has 1,681 precincts.
Each of those precincts holds its own caucus meeting.
The first step is for voters to gather in a room and organize themselves according to their first choice candidate. Then, there's a count.
Candidates need at least 15% of the people in the room.
Next step: realignment
Supporters of candidates who did not meet the 15% threshold can either align with a different candidate, recruit supporters for other candidates, or simply leave. That's why a caucusgoer always needs to have a second choice in mind.
Finally, the candidate with the most people in their corner gets the most delegates from that particular caucus meeting. This repeats all over the state.
The candidate who collects the most delegates from all the different precincts wins the Iowa caucus.
Later in the year, there are county conventions, then district conventions and finally a statewide convention.
Republican caucus meetings are different from Democratic caucuses: those voters make their choices in private.
The Iowa caucuses are considered a big deal because winning that first contest of the season can get candidates a lot of press coverage and bolster their popularity as they continue to the next states.
Seven out of 10 Democratic caucus winners have gone on to win the Democratic presidential nomination.
Only three out of eight Republican caucus winners went on to win the Republican nomination.
As for the presidency, only six out of the 18 caucus winners since 1972 have gone on to take the White House.
The Iowa caucuses will be held on Feb. 3 this year, and Annenberg Media will be there. Follow our coverage: #USCinIowa
