How do the Iowa caucuses work?
This relatively small number of voters, and their overwhelmingly white makeup, routinely bring Iowa's caucuses under attack by outsiders who want more clout for their own states. Only 5 percent of Iowa's electorate is Hispanic and only 3 percent is black, compared with a national electorate that is 16 percent Hispanic and 12 percent black.
For their part, Iowans jealously guard their first-in-the-nation nominating contests.
While both parties in Iowa use the caucus system to choose candidates, Republicans and Democrats go about things differently.
For the GOP, the caucuses are simply a straw poll, meaning the results are not binding. While Democrats use the caucuses to choose delegates who are expected to support their favored candidate, Republicans handle that later at county and district conventions.
After electing a temporary chair to run the meeting and a secretary to record the proceedings, any Republican who chooses can briefly speak in favor of a candidate. Ballots are then passed out and participants mark their choices in private. Those ballots are quickly counted and the results called into party headquarters, where they are posted online as they are received.
Any Republican voter can participate, including those who register when they arrive at the event. People too young to vote can also take part if they will be 18 by the general election.
Democrats, when there are multiple candidates, take a more convoluted approach.
Democrats break into preference groups at their caucuses, publicly declaring which candidate they favor. Candidates must get support from 15 percent of those attending the caucus in order to receive votes. Once they break into those groups, activists try to attract those whose candidates have fallen short of the 15 percent threshold.
After the results are reported to party headquarters, the numbers are run through a formula that changes the value of votes based on a county-by-county analysis of Democratic performance in the last gubernatorial and presidential elections.
"The Republican caucuses and Democratic caucuses are two different beasts," said Democratic strategist Phil Roeder. "In the big picture, it makes for a very different result."
Democratic strategist Jerry Crawford put it another way: "Democrats always like to make things more difficult."
Although the Republicans have a simpler system, caucuses by both parties require more time and greater participation than in a primary election.
Activists said that level of commitment means that for a candidate to be successful, he or she must make connections with voters, then build an organization that can get them to their precinct gatherings.
"People still expect to see the candidates in person," said Steve Scheffler, who heads the influential Iowa Faith and Freedom Coalition. "The candidates who have spent the most time here will benefit."
Associated Press writer Libby Quaid in Washington contributed to this report.
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