Before 1937 political scientists had begun to decribe the US political system as one of pluraism and interest groups. After 1937 some justices moved haltingly to write the theory of interest group plualism into constitutional theory in ways that would allow them to uphold economic regulation while taking a more active role in policing legislation dealing with civil liberties. To do so they had to develop an account of “fundamental rights” that were enforceable aagainst the states through the Due Process Clause.