Well, since you asked, the government has a positive duty to decide who is and who is not capable of exercising normal, responsible and mature judgment. For example, if you are a minor, you cannot enter into an enforceable contract. A guardian must be appointed to act on your behalf. Minors can argue that this is blatant age discrimination and – under your interpretation of the 14th amendment – should be unconstitutional. So far, no court has found it so, but I’m sure that interpretation will be argued to exist somewhere in the emanations and penumbras of the constitution. That same discrimination is exercised in the case of the mentally incompetent, the comatose and the dead. I know- I know it’s discriminatory, but that’s the way our society oppresses the insane, the unconscious and the expired.
”What about the 4th Amendment... "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."
What's the probable cause for seizing a person of low intelligence, if they have committed no crime?
Well, here again you have some people who will take words that the government can’t bust into your house without a warrant and say that means that we they can’t stop two imbeciles from producing more imbeciles. I’m not sure that I see the connection, but I’m sure that you do.
Your concern for the insane is widely shared, however, by the more enlightened among us who decided a few decades ago that we were depriving these poor creatures of their constitutional rights by warehousing them in (what an older generation called) insane asylums.
So we closed the asylums. You will now find the freed former inhabitants exercising their constitutional rights as they roam the our cities with their belongings piled into shopping carts and sleeping under bridges, using the public bathrooms to procreate and the public streets to defecate.
But getting back to the issue of judges and the courts, the point I have been trying to make is that these are rightfully public policy decisions to be decided by legislatures and city councils, not judges who wish to exercise some Olympian power over the rest of us. Even the wackiest city councils eventually get it. Los Angeles just passed a law making it illegal to empty your bladder or your bowels on the public street. Civil libertarians are up in arms over this denial of their constitutional rights.