That said, no government can pass laws outlawing insanity.
OTOH, a squirt gun is a toy, not a weapon, and a temporary public ban on protesters carrying them in downtown Tampa during the RNC convention is not something that goes against the right to bear arms, nor the right to protest.
But you know that, right?
There is no need to temporary ban such items, and if there was a problem with them in first place, there would be ban on them every where. Not just for this convention.
The role of the thought police is ever increasing.