Another reason for retracing our steps will doubtless be seen by Congress in the late manifestations of public opinion upon this subject. We live in a country where the popular will always enforces obedience to itself, sooner or later. It is vain to think of opposing it with anything short of legal authority backed by overwhelming force. It can not have escaped your attention that from the day on which Congress fairly and formally presented the proposition to govern the Southern States by military force, with a view to the ultimate establishment of Negro supremacy, every expression of the general sentiment has been more or less adverse to it. The affections of this generation can not be detached from the institutions of their ancestors. Their determination to preserve the inheritance of free government in their own hands and transmit it undivided and unimpaired to their own posterity is too strong to be successfully opposed. Every weaker passion will disappear before that love of liberty and law for which the American people are distinguished above all others in the world. How far the duty of the President "to preserve, protect, and defend the Constitution" requires him to go in opposing an unconstitutional act of Congress is a very serious and important question, on which I have deliberated much and felt extremely anxious to reach a proper conclusion. Where an act has been passed according to the forms of the Constitution by the supreme legislative authority, and is regularly enrolled among the public statutes of the country, Executive resistance to it, especially in times of high party excitement, would be likely to produce violent collision between the respective adherents of the two branches of the Government. This would be simply civil war, and civil war must be resorted to only as the last remedy for the worst of evils. Whatever might tend to provoke it should be most carefully avoided. A faithful and conscientious magistrate will concede very much to honest error, and something even to perverse malice, before he will endanger the public peace; and he will not adopt forcible measures, or such as might lead to force, as long as those which are peaceable remain open to him or to his constituents. It is true that cases may occur in which the Executive would be compelled to stand on its rights, and maintain them regardless of all consequences. If Congress should pass an act which is not only in palpable conflict with the Constitution, but will certainly, if carried out, produce immediate and irreparable injury to the organic structure of the Government, and if there be neither judicial remedy for the wrongs it inflicts nor power in the people to protect themselves without the official aid of their elected defender--if, for instance, the legislative department should pass an act even through all the forms of law to abolish a coordinate department of the Government--in such a case the President must take