I think the crowd turned on Jesus because He didn’t fulfill their expectations of a real Messiah. They were still looking for a military hero to deliver them from the hated Romans. They missed the point that He was riding a lowly donkey. They were looking for a general like Judas the Hammer. Over the next few days, it became obvious Jesus wasn’t a military revolutionary. He was a suffering servant who was going to be handed over to the Romans. He failed them, and they turned on Him in vicious rejection.