Before a US presidential election, every state (and territory) has to vote to decide which candidates to run in – but how that decision is made varies from state to state. Some have area codes, while others hold meetings.
Area code is a relatively simple process that is similar to any other choice. Essentially, you go to your polling station, which can range from a school to a sports complex, and check your favorite candidate on a ballot. In general, any candidate who receives at least 15 percent of the vote is entitled to earn delegates, elected officials who vote to decide who to vote for at the National Congress as the party's presidential candidate. These delegates are then divided among the candidates in proportion to the number of votes they have received. Because the primaries are short and simple, they use almost all states and territories today to select presidential candidates.
However, there are several holdouts that still opt for caucuses, a manual (and more complicated) voting process rooted in American elections in the late 1
If your state has an area code, there is a pretty good chance that you can get in and out without speaking to more than one or two people – and it might even be a surprise if someone tries to get you convince them to vote for a particular candidate. For democratic assemblies, however, this is an essential part of the process. Before the first count, people try to convince undecided voters to join their group (or supporters of a candidate who does not appear to meet the viability threshold), and after the first count there is another wave of campaigns to support supporters demand unprofitable candidates. In addition to all the manual counting and recounting, this means that caucus participants can rely on being present as primary participants for hours longer.
Caucuses are a great way to see how citizens really think about the President's hope in a deeper area. Personal levels more than polls and statistics can often tell us, but the general annoyance – not to mention fear before imprecise vote counting – has led to more and more countries switching to primaries in recent years. As reported by Business Insider in 2020 there will only be eight venues for meetings: Iowa, Nevada, North Dakota, Wyoming, Kentucky (Republicans only), American Samoa, the Virgin Islands and Guam.  Because Iowa's assemblies always come first, they're often seen as more important than some others – find out why.
[h/t Business Insider]