“We’ve seen from the early days of his presidency even, and before that during his first campaign in 2016, how important crowd size is to him. It gives him a lot of joy and energy being with large crowds. He feeds off their energy. It’s almost like a source of comfort for him,” said Matthews, who served as a deputy press secretary in the Trump White House.

The Secret Service doesn’t like to be taxed and outdoor rallies are viewed as “onerous” by them.

Washington Post: