“ The granting of an order or writ to maintain or restore the status quo pending the outcome of existing litigation, which really is what was done here, has been practised by the courts of the country since before the Constitution was adopted; and the claim that relief of this nature cannot be granted, even upon condition that ample security be given to make good any loss that may be sustained thereby, without encroaching upon the due process of law secured by the Constitution, is manifestly without merit. ”

“ This view has prevailed through a century of practices in reviewing judgments and decrees dismissing causes for want of jurisdiction or for other reasons not decisive of the merits. And it is settled that a proceeding in mandamus is an independent adversary suit, and a judgment awarding or refusing the writ is a final judgment within the meaning of the statute. ”

“ If the Commission rescind its order, the suit shall be dismissed; if it alter the order, the same in its changed form shall take the place of the original, and judgment shall be rendered thereon as though the last action of the Commission had been taken at first; (§ 6570) in addition to all other remedies, the Commission, and likewise any party in interest, may compel compliance with an order of the Commission by a proceeding in mandamus, injunction, or other appropriate civil remedy. ”