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Tonight, the Iowa caucuses will take place, a pivotal moment for Democrats that might very well influence the rest of the 2020 election. But what exactly is a caucus? And how is it any different from a primary? Well, if you’ve ever wondered why Iowa’s caucuses have such enormous implications for the presidential election or how the actual process works, below, you’ll find all of the answers to your burning questions.




What are Iowa’s caucuses and how are they different from primaries?

In short, Iowa’s caucuses involve a gathering of a party’s registered voters to discuss preferred presidential candidates, unlike a primary in which voters cast a secret ballot. As PBS writes, state governments typically run primaries and caucuses are run by the parties themselves. Currently, just three states still rely exclusively on caucuses over primaries, including Nevada, Wyoming, and Iowa, and in each of those states, Democrats and Republicans establish their own rules on how caucuses will proceed.


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How will the Iowa Democratic caucus work?

Politico has an excellent, illustrated guide on how Iowa’s Democratic caucus works. Here’s the process, in short:

Democratic voters gather at designated caucus sites, like community centers or libraries.

They separate into groups based on preferred candidates (or remain undecided).

Each group is counted to determine whether candidates are “viable.” Generally, a candidate must receive at support of at least 15% of participants to be considered viable.

If a candidate fails to meet the viability threshold, their supporters are given the option to abandon their group and join another or persuade others to join theirs, in a process known as “realignment.” (They’re also allowed to opt-out of the process entirely and just go home or join the undecided group.)

When all candidates have finally achieved the viability threshold, a count is taken again. Every viable candidate is then afforded at least one “delegate” that is elected by that group. The more supporters they receive, the more delegates they are permitted.

Using a formula, the state then determines how many “state delegate equivalents” a candidate has won at each caucus site. It gets a little complicated from here, but generally speaking, the winner of the most state delegate equivalents wins the most candidates sent to the Democratic National Convention, and thus, wins the Iowa caucus, as Politico

The Republican caucus, by comparison, is pretty simple and just involves a secret ballot process, rather than a public one, in the determination of its delegates.

So why do they matter?

It’s the first time any state’s voters actually weigh in on a presidential election—and that can carry a lot of weight. Think of how early voting states can impact the results of other states’ primaries and caucuses, donors and their contributions, and general media attention.


As Vox’s senior political correspondent Andrew Prokop wrote in 2016, every winner of a major presidential party nomination since 1980 won either the Iowa caucus, the New Hampshire primary or both. (Hillary Clinton won the 2016 Iowa caucus; President Trump lost the caucus but won the New Hampshire primary.) To demonstrate just how influential this caucus can become, Prokop referred to Obama’s win in Iowa back in 2008 as a significant game-changer. “On the day of the caucuses, he trailed Hillary Clinton by more than 20 points in national polls. But days after he won there, he shot up to within 5 points of her.”

Will 2020's caucuses be any different from years’ past?

Yes. Unlike caucuses of decades’ past, this year, raw vote counts for each candidate before and after the realignment process will be made public in Iowa. The problem? Well, while it’s intended to boost transparency around the state’s caucus process, it means several candidates could claim a win in Iowa, by winning one or both of the vote counts. While it wouldn’t affect the delegate count, it might, at least, influence the narrative around candidates’ wins or losses after the caucus.


This story was published on 1/21/20 and updated on 2/3/20 to reflect the timing of the caucuses.