He insists that the present levy is not a true tax, but a penalty imposed for the purpose of suppressing traffic in a certain noxious type of firearms, the local regulation of which is reserved to the states because not granted to the national government. The case is not one where the statute contains regulatory provisions related to a purported tax in such a way as has enabled this Court to say in other cases that the latter is a penalty resorted to as a means of enforcing the regulations. Nor is the subject of the tax described or treated as criminal by the taxing statute. Here 2 contains no regulation other than the mere registration provisions, which are obviously supportable as in aid of a revenue purpose. On its face it is only a taxing measure, and we are asked to say that the tax, by virtue of its deterrent effect on the activities taxed, operates as a regulation which is beyond the congressional power.
Every tax is in some measure regulatory.
To some extent it interposes an economic impediment to the activity taxed as compared with others not taxed. They will not undertake, by collateral inquiry as to the measure of the regulatory effect of a tax, to ascribe to Congress an attempt, under the guise of taxation, to exercise another power denied by the Federal Constitution. As it is not attended by an offensive regulation, and since it operates as a tax, it is within the national taxing power. We do not discuss petitioner's contentions which he failed to assign as error below.