That’s a good question, but there are in fact other instances where clauses in the Constitution are defined as preambles. In Article I, Section 8, Clause 8, one of the powers of congress is stated as: “To promote the Progress of Science and useful Arts, by securing for limited Times to Authors and Inventors the exclusive Right to their respective Writings and Discoveries.” The power granted to congress is to grant patents and copywrites. The words, “[T]o promote the Progress of Science and useful Arts” is seen as a preamble. There are other ways to promote the sciences and useful arts aside from copywrites and patents, yet those are the specific rights granted. There are also other benefits to copywrites and patents, such as securing personal property rights to the inventor or writer.
If you look at the 4th amendment, it states: “The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized.” The first part of the amendment states a general principle or arguabley, a preamble. It is the second part of the amendment which actually supports that objective: “no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized.” You could argue that everything before “no warrants” is unnecessary preamble.
If you are between the ages of 17 and 45, you are in fact part of the “unorganized” Massachusetts militia, and subject to call up to aid in putting down insurrection or riot. (See M.G.L. c 33 secs. 2 and 3) Upon your call up, you are deemed part of the organized militia.
By the way, I am far from an expert in this area, and have no idea how the Court will rule, but I do enjoy the arguments being made on both sides. This is certainly an opportunity for the Roberts Court to shake things up.