I've heard the argument that if we take the Tenth Amendment seriously and say that all powers not delegated to the federal government are to be left to the states and the people, then the Air Force must be unconstitutional. But, I find that line of reasoning to be fatally flawed because Article I Section 8 gives Congress the power to raise and support armies and the Air Force does everything an army does, except it just happens to have planes. If internet speech is protected under the First Amendment and the Second Amendment applies to weapons that didn't exist during the Revolutionary War, then the power to raise armies should include the power to create an air force, as planes didn't exist during Founding generation. Besides, Article I Section 10 says that states are forbidden to keep troops and members of the Air Force are troops. If states are forbidden to do something, that power belongs to the federal government.