Above all, the Constitution attempts to create a deliberative democracy, that is, a system that combines accountability to the people with a measure of reflection and resason-giving.  In the last decades, many people have discussed the framers’ aspiration to deliberative democracy. Their goal has been to show that a well-functioning democraic system attempts to ensure not merely responsiveness to the people through elections but also an exchange of reasons in the public sphere. In a deliberative democracy, the exercise of public power must be justified by legitimate reasons – not merely by the will of some segment of society, and ineed not merelybythe will of the majority.

Cass R. Sunstein, Why Societies Need Dissent, p. 150

Diversity, openness, and dissent reveal actual and incipient problems. They improve society’s pool of information and make it more likely that serious issues will be addressed. I do not deny that great suffering can be found in democracies as elsewhere. There is no guarantee, from civil liberties alone, that such suffering will be minimized. One reason is unequal distributions of political power, which decrease the likelihood that important information will actually reach public officials and that such officials will have the proper incentive to respond to suffering. But at least it can be said that a society which permits dissent and does not impose conformity is in a far better position to be aware of, and to correct, serious social problems.

Cass R. Sunstein, Why Societies Need Dissent, p. 149

Federalism itself -the provision of both national and state governments – was, and remains, an engine of diversity, creating “circuit breakers” in the form of a variety of sovereigns accountable to separate regions.  In the federal system, social influences may produce error in some states, and states can certainly fall into cascades. But the existence of separate systems creates a check on the diffusion of error. In this respect, federalism permits states to restrain one another. A particularly important part of this process involves the right of individual citizens to exit. If one sate oppresses its citizens, they have the freedom to leave. That very freedom creates a before the fact deterrent to oppressive legislation. It also creates an after-the-fact safeguard. In this sense, the right to travel from one sovereign state to another is first and foremost a political right, akin to the right to vote itself. Competition among the states provides some protection against the movement of unjustified cascades from one state to another. And if a form of group polarization occurs in one state, the federal system ensures that other states might come to different views. Here, too, we can find a safeguard of liberty.

Cass R. Sunstein, Why Societies Need Dissent, p. 154

Justice Louis Brandeis protest against the Court’s veto (under the Fourteenth Amendment’s due process clause), of an Oklahoma law mildly regulating the ice business: ” It is one of the happy incidents of the federal system that a single courageous state may, if its citizens choose, serve as a laboratory, and try novel social and economic experiments without risk to the rest of the country.”

As found in Fred Rodell: Nine Men, p. 228.

Wherever the title of streets and parks may rest, they have immemorially been heldin trust for the use of the public and time out of mind, have been used for the purposes of assembly, communicating thought between citizens, and discussing public questions. Such use of the streets and public places has, from anceint times, been a part of the privileges, immunities, rights and liberties of citizens.

Hague v. CIO, 307 US 496 (1939)

Sidewalks in Cyberspace PDF