I thought maybe it was a signal of support and warning to any no - goods that the military supports returning the power to the people.
Someone said on another thread that the military that came down the stairs were passing out ponchos. They didn’t indicate this but I saw several of the clear plastic umbrellas, too, being used by some of the ladies, so perhaps they were passing out those as well.
Cheney was seated behind Bush and tried to help W with the poncho he was struggling with. Short vid here: