Really? We allow this all the time.You can protest wherever you want, so long as you do not keep other people from enjoying THEIR rights.
Union picket lines do this constantly.
You have a right to go someplace unimpeded.
Yet Public sector unions always picket, which is a protest, outside the entrences of public buildings, and impede people's ability to get into them.
They block parking lots at Government buildings and purposely slow the rate of cars getting into the parking lots.
And this ability to impede the rights of others is enshrined in law.