In Iowa, voters arriving at their caucus site will fill out a card that lists their first choice. Those results will be tabulated and will determine the results of the “first alignment.”

But that’s not the end of the night.

Caucus-goers whose first-choice candidate fails to get at least 15% of the vote can switch their support to a different candidate. The threshold can be higher at some precincts. If voters don’t choose another candidate, their vote won’t count in the final alignment. They can choose “uncommitted” — but that choice only gets reported if it, too, gets at least 15% of the vote.

The results of this stage will be tabulated to determine the caucuses’ “final alignment.” Only candidates who receive at least 15% of the vote at that precinct — the so-called viable candidates — will be counted in the final alignment. Non-viable candidates get zero votes in the final alignment.

There’s one more step.

The final alignment votes are then used to calculate the number of state convention delegates awarded to each candidate.