There are a few things you need to keep in mind.
First, if a precinct splits, say, 30% for Sanders, 15% for Biden, and everybody else under 15%, then the 55% that didn’t vote for either one can switch to one of those two. If most of them go to Biden, it could end up being a 50-50 split in that precinct.
Second, I said “can” switch. If a voter’s candidate does not get 15% in the first round of voting, they can choose to leave the caucus rather than vote for someone else.
Third - there is an exception to this; if, say, Sanders gets 30% and nobody else gets 15%, then there is no second round of voting; while Sanders is the only one with votes there, nobody who didn’t vote for him can change their mind.
[QUOTE=Nevada 2020 Democratic National Convention Delegate Selection Plan, Rule III.A.12]
Upon the conclusion of the announcement of results from the initial alignment, if and only if, there are any non-viable preference groups, the eligible caucus attendees in those groups will have up to another fifteen (15) minutes to realign with a viable group.
[/QUOTE]
Being able, or not able, to switch, is important, as Nevada awards its delegates to the national convention based on the “head count” at the caucuses. In effect, it is a primary with (usually) a two-step preferential vote.
I have a feeling that, if there are districts where Sanders is the only one with at least 15%, there will be different interpretations as to counting how many people actually voted for him.
“100 people showed up, and 30 voted for Sanders, while nobody else got at least 15, so Bernie is credited with all 100 votes.”
“No, he only gets 30 votes, since there was no second round.”
“It is implied that, since he was the only candidate, everybody would now vote for him.”
“No, because the other 70 could also go home and not be counted.”