There is, of course, room for error and confusion in this process. Long lines can delay results. Voting machines can malfunction. A close race can require a recount. Just think “Florida 2000” if you’re tempted to believe regular voting can’t go wrong.

But the sort of systemwide breakdown we saw in Iowa is extremely rare in primaries.

Caucuses

In caucuses like Iowa’s, participants must show up at their precinct at a specific time and publicly declare their allegiance.

Caucusgoers physically align themselves — Buttigieg supporters here, Warren supporters there — and precinct leaders record the totals for each candidate. The candidates who don’t have enough support to be “viable” are eliminated; their supporters have a chance to realign with viable candidates; and precinct leaders record the new totals.

Then the leaders have to calculate how many state delegate equivalents each candidate has earned and record that, too. The numbers can be fractions; for instance, in Polk County, which includes Des Moines, Bernie Sanders received 106.88 state delegate equivalents based on the initial results.

This process involves actual calculations, not just a simple count. All of the recording is done by hand, on work sheets. And at the end of the night, the precincts have to submit three sets of results — the first alignment and the final alignment and the state delegate equivalents — to the state party.