There is another explanation.
People who are going to vote for Clinton will vote for Clinton. No need to go to a rally.
People who are going to vote for Trump will vote for Trump. They won't go to a rally for Clinton.
People who are going to vote for Johnson will vote for Johnson. They won't go to a rally for Clinton.
Undecided voters are not excited over the prospect of a rally with the Democratic bridesmaid. They won't go.
The only remaining people are those who are looking for free coffee and donuts, the rally organizers, and any relatives they dragged along. That adds up to about 30, it appears.
