Do we have any evidence that number of people at campaigning events correlates to more votes? If not, why would we conclude that? Is it not (in absence of any

Do we have any evidence that number of people at campaigning events correlates to more votes? If not, why would we conclude that? Is it not (in absence of any evidence) equally plausible that the type of voter that will vote for Trump is more predisposed to attend a campaign event than other voters?