U.S. Election Research · January 16, 2020

What really happens on Iowa Caucus night?

By edison

By Sarah Dutton

Since 1972, the Iowa caucuses have represented the first presidential nomination contest and therefore receive a great deal of attention. They can provide surprises (Barack Obama, who trailed Hillary Clinton in national polls, won Iowa in 2008), catapult a nationally unknown candidate into the lead (Jimmy Carter in 1976) or be nail-biters (the 2012 Republican caucus was the closest in Iowa history with Rick Santorum edging Mitt Romney by less than a tenth of percentage point, and the 2016 Democratic caucus had Hillary Clinton defeating Bernie Sanders by a quarter of a percent). 

For those of us who don’t live in Iowa, the caucuses can be downright confusing; the caucus process is very different from a primary, which is what most voters are familiar with.  What is a caucus? Do voters cast votes? How does a candidate “win” in Iowa?  How are the results determined?  Here is a primer on the Democratic caucuses that will help explain what you’ll see, hear or read reported on February 3, and what it means.

The Democratic caucuses are essentially community meetings. They can be held in many types of places, including schools and churches.  Unlike in a primary, where voters can vote throughout the day and evening, caucuses begin throughout the state at a uniform time – 7 p.m. Central Standard Time.

When they enter the caucuses, many Democratic caucus attendees will have a candidate in mind to support.  Once the caucus has begun, voters divide into groups according to which candidate they support, often referred to as their “first preference.”  Undecided voters also form a group supporting “Uncommitted.  At this point, at least 15% of caucus-goers at that site must support a candidate for the candidate to reach the “viability” threshold.  Voters who support candidates receiving less than 15% must then realign themselves with another candidate, or they can try to persuade other voters to back their candidate until the 15% threshold is reached.  

For instance, if Candidate A doesn’t receive 15% support, then their supporters must choose from the other viable candidates in the race (Candidate B, C, D, etc.) or convince more voters to back Candidate A.  Since this is a fluid process, voters may end up supporting a different candidate than they did when they first entered the caucus. And all this occurs within the privacy of the caucus location.  

Once the final candidate groups are formed, support for each viable candidate is translated into “state delegate equivalents” – the number of delegates who will go to the Iowa state Democratic convention (and eventually the national Democratic convention) in support of each candidate.  

The process can throw a curve ball to pre-election pollsters in Iowa. Polls conducted before the caucuses may accurately measure the first preference of voters there, but not reflect the post-viability realignment that occurs during the caucus.  This is especially a concern when there is a large field of candidates running for the nomination, many of whom will not meet the viability threshold. 

In caucus states, Edison Research conducts an entrance poll, rather than an exit poll; voters complete the entrance poll questionnaire as they enter the caucuses. (By contrast, in states with primaries, voters are asked to fill out a questionnaire as they leave their voting place, after they have voted.)  That’s because caucus-goers all leave the caucus at the same time, when the grouping process is over; it would be challenging to sample voters as they all leave their caucus together.   

Edison Research has conducted the Iowa Caucus entrance poll since 2004. On Caucus night, Edison staff will be interviewing voters as they enter Caucus sites. Edison will measure caucus goer’s initial preference and will later tabulate both the pre and post “viability” vote in each location (also referred to as “first alignment and “final alignment”).  Also for the first time the Iowa State Democratic Party will be reporting three sets of results – the first alignment preference, the final alignment preference and the state delegate equivalents.  So be prepared for different candidates leading each set of results and possibly different orders of finish. 

That’s the caucus process in a nutshell. Enjoy watching or reading about the results! 


About Edison Research
Edison Research conducts survey research and provides strategic information to a broad array of clients, including Activision, AMC Theatres, Disney, Dolby Laboratories, Google, Oracle, the U.S. International Broadcasting Bureau, Pandora, Samsung, Siemens, Sony, The Gates Foundation, and Univision. Edison is the leading podcast research company in the world and has conducted research on the medium for NPR, Slate, ESPN, PodcastOne, WNYC Studios, and many more companies in the space.  Another specialty for Edison is its work for media companies throughout the world, conducting research in North America, South America, Africa, Asia, Australia, and Europe. Edison is also the leading provider of consumer exit polling and has conducted face-to-face research in almost every imaginable venue. Since 2004, Edison Research has been the sole provider of Election Day data to the National Election Pool, conducting exit polls and collecting precinct vote returns to project and analyze results for every major presidential primary and general election.

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