Then there are the people away from home to consider, and caucusgoers who speak a language other than English. The list of accessibility challenges helps explain why in Iowa, a state of more than three million people, the largest number to participate in a Democratic caucus — at least as of Monday — was about 240,000 in 2008.

Aware of these longstanding concerns, Democratic National Committee members voted in 2018 to encourage states that held caucuses to switch to primaries, and to require the caucus states that remained — like Iowa and Nevada — to find another way for people to participate.

In Iowa, Democrats spent months trying to design a “virtual” caucus system, which would have allowed participation through a phone call, but the Democratic National Committee rejected that proposal over security concerns. They also considered mailing absentee paper ballots, but ditched that idea because of fears that it hemmed to close to being a primary.

In the end, they landed on satellite caucuses, which went into action on Monday.

How the satellite caucuses worked

To host a satellite caucus, people unable to attend their regular precinct caucus were required to apply, and a state party panel approved each of the gathering locations. The Iowa Democratic Party initially announced a list of 99 satellite caucuses, but later nixed 12 of them, leaving a total of 87 sites.

The locations were variously meant to accommodate students, workers, older people, people with disabilities, people who speak a language other than English, people wintering in another state and people living abroad. Any registered Iowa Democrat was allowed to participate. Sixty of the 87 sites were in Iowa; the rest were elsewhere in the country and at three overseas locations.

Party officials set up a formula to determine how many state delegate equivalents were allotted to the satellite caucuses, based on turnout at the events (more on that below). The party said more than 1,700 people had registered for a satellite caucus, though more may have shown up on Monday. Of those who registered, officials said a significant majority were out of state or at an international site.

Sanders runs up the score

The Sanders team appeared to make the most concerted effort among the Democratic campaigns to capitalize on the new caucus format.