https://m.mic.com/articles/122531/on...-is#.cVDNZSktJ
Key takeaway from the link above:
"What it means: While Sanders ability to attract huge crowds is a key narrative of the campaign so far,
crowd size is a notoriously imperfect indicator of a candidate's prospects in a coming election. In the days leading up to the 2012 presidential election, Republican nominee Mitt Romney played to roaring crowds in a number of states, including Ohio. On Election Day, he would lose there by more than 100,000 votes."
I believe the largest single campaign rally in the U.S. was at Fenway Park in '68 where 60,000+ turned out for our beloved president to-be... .Eugene McCarthy.