The correct answer is if the demonstrators endanger public safety.
The government can stop a public protest of its policies if the demonstrators endanger public safety.
People have the right to express their own ideas in public. They also have the right, protected by the U.S. Constitution of assembly and to protest in public places. They do it in public areas to gain attention and publicity. The Press can cover its demands. But they have to do it in order, respecting other people, places, homes, streets an,d business. During a public protest, people are not allowed to vandalize private or public property. If they do so, the government can stop a public protest if the demonstrators endanger public safety.