Frankfurter saw justices with ideas different from his own as part of a more liberal "Axis" – these opponents were chiefly Justices Black and Douglas, but would also include Murphy and Rutledge; the group would for years oppose Frankfurter's judicially restrained ideology. Douglas, Murphy, and then Rutledge were the first justices to agree with Hugo Black's notion that the Fourteenth Amendment incorporated the Bill of Rights protection into it; this view would later mostly become law, during the period of the Warren Court. For his part, Frankfurter would assert that Black's incorporation theory would usurp state control over criminal justice by limiting states' development of new interpretations of criminal due process.