In Texas, where the local passenger traffic is slight, trains carry one sleeping car. These trains, unlike trains having two or more sleepers, are without a Pullman conductor. The sleeper is in charge of a porter who is subject to the train conductor's control. Porters on Pullmans are colored and conductors are white. P after due hearing ordered that 'no sleeping car shall be operated on any line of railroad in the State of Texas . . . unless such cars are continuously in the charge of an employee . . . having the rank and position of Pullman conductor.' Pullman (Ps) this action in a federal district court to enjoin D's order. Pullman porters were permitted to intervene as complainants, and Pullman conductors entered the litigation in support of the order. the court enjoined enforcement of the order. Ps argued that the order was violative of the Equal Protection, the Due Process and the Commerce Clauses of the Constitution. The intervening porters claimed discrimination against Negroes in violation of the Fourteenth Amendment. D appealed.