defence must finally rest upon his ability to establish the facts by competent proofs. Besides; in many instances the evidence, upon which the president might decide, that there was imminent danger of invasion, might be of a nature not constituting strict technical proof; or the disclosure of the evidence might reveal important state secrets, which the public interest, and even safety, might imperiously demand to be kept in concealment.[1] The act of 1795 was manifestly framed upon this reasoning. The president is by it necessarily constituted, in the first instance, the judge of the existence of the exigency, and is bound to act according to his belief of the facts. If he does so act, and decides to call out the militia, his orders for this purpose are in strict conformity to the law; and it would seem to follow, as a necessary consequence, that every act done by a subordinate officer in obedience to such orders is equally justifiable. The law contemplates, that under such circumstances orders shall be given to carry the power into effect; and it cannot be, that it is a correct inference,. that any other person has a right to disobey them. No provision is made for an appeal from, or review of the president's opinion. And whenever a statute gives a discretionary power to any person to be exercised by him upon his own opinion of certain facts, the general rule of construction is, that he is thereby constituted the sole and exclusive judge of the existence of those facts.[2]
§ 1207. It seems to be admitted, that the power to call forth the militia may be exercised either by requisitions upon the executive of the states; or by orders