“Caucusing is a meeting, not an election. At the end of the meeting there is an election...”
Looks like you misunderstand it also, since that sentence contradicts itself.
A caucus takes place on predetermned date, and in the process there is a vote, and it is only open to citizens of Iowa, and it is as simple as that.
Or you misunderstand. The word ‘caucus’ has a meaning.
In the case of Iowa, to select a candidate there are a whole series of caucuses and then votes, at different levels from precinct on up through the state, not a single thing. A caucus however does not have to include an election.