Since they are allowing symbols, I see nothing wrong with them banning the real thing as they could be used as a weapon or a place for concealing them.
What y'all are saying is that it's ok to be hit on the head with a wooden menorah, but it's not ok to be hit with a cross. Thinking about it, one could carry metal crescents that could be sharp enough to be used as sickles and do some beheading along the inaugural parade route... it's ok, as long as you don't carry a cross!