Now this is some serious grass-roots organizing...

Although more than 7,000 delegates to the county convention had been elected at the Jan. 19 caucuses, the county party booked a room at Bally’s
with a capacity of 5,000.
Few people expected the 7,000 elected delegates to show, but it was entirely unsurprising that the Clinton and Obama campaigns, locked in a tight
delegate battle that could go all the way to the national convention, would call their supporters and tell them to show up at Bally’s so they could
be alternates to replace the no-shows.
Sure enough, that’s what happened. There were 6,000 people in the hall when the fire marshal intervened, and Bally’s management estimated 4,000
people in the hallway outside.
The problem was that there wasn’t a clean and credible process for seating alternates.
If the campaigns are doing this here...you can bet the same is going on everywhere.