Before leaving the subject of the Federal courts one feature of the judicial negative deserves further notice. The fact that it is not exercised until a case involving the law in question is brought before the court in the ordinary course of litigation is often referred to by constitutional writers as one of its chief merits. And yet until a competent court has actually declared a legislative act null and void, it is for all practical purposes the law of the land and must be recognized as such. It may vitally affect industry and commerce and require an elaborate readjustment of business relations. It may even be years after such an act is passed before a decision is obtained from the court of last resort. And if the decision annuls the law, it does so not from the time that the judgment of the court is rendered, but from the time the act in question was originally passed. This retroactive character of the judicial veto is strongly suggestive of the _ex post facto_ legislation which the Constitution expressly forbids. By thus invalidating the law from the beginning it may leave a vast body of business contracts without legal protection or support. As a consequence, it is impossible for any one, be he ever so well informed, to know just what legislative acts are valid and what are not. The amount of uncertainty which this introduces into business relations is more easily imagined than described. America can claim the rather questionable distinction of being the only important country in which we find this uncertainty as to the law, since it is the only one in which the courts have a negative on the acts of the legislature. That we have ourselves realized the disadvantages of the system is shown by the changes made in the constitutions of several states with a view of diminishing the frequency of the judicial veto. These provisions make it the duty of the judges of the supreme court of the state to give their opinion upon questions of law when required by the governor or other branch of the law-making authority.[102] In so far as constitutional provisions of this sort have been intended to prevent the evils resulting from a deferred exercise of the judicial veto, they have largely failed to accomplish their purpose. This has been due to the attitude of the courts, which have held that an opinion thus given in compliance with a constitutional requirement is not binding upon them when the question is raised again in the ordinary way in the trial of a case. CHAPTER VI THE CHECKS AND BALANCES OF THE CONSTITUTION Two features of this system, the difficulty of amendment and the extraordinary powers of the judiciary have been discussed at some length. Both, as we have seen, were designed to limit the power of the popular majority. This purpose is no less evident when we view the Constitution as a whole.