Wherever the title of streets and parks may rest, they have immemorially been held in trust for the use of the public and, time out of mind, have been used for purposes of assembly... and discussing public question. Such use of the streets and public places has, from ancient times, been a part of the privileges, immunities, rights, liberties of citizens. The privilege of a citizen of the United States to use the streets and parks for communication of views on national questions may be regulated in the interest of all... but it must not, in the guise of regulation, be abridged or denied.
