Made up out of whole cloth? I don't think so. The Supreme Court considers certain rights fundamental even though they are not enumerated in the Constitution, because it's clear most Americans would have seen them as basic rights even before the Constitution was written. The Court has phrased its standard for fundamental right slightly differently in its decisions, but the most common phrasing of the "magic words" is that to be fundamental, a right must be so "deeply rooted in the history and traditions of this Nation" that they are "implicit in the concept of ordered liberty."
The Court has recognized for a long time now that marriage between a male and a female is a fundamental right:
"We are dealing here with legislation which involves one of the basic civil rights of man. Marriage and procreation are fundamental to the very existence and survival of the race." Skinner v. Oklahoma, 316 U.S. 535, 541 (1942).
And there are similar statements in Supreme Court decisions going back to the 1800's. But notice I said marriage between a male and a female. There is no fundamental right to polygamy, or bigamy, or to marriage between parties very closely related by blood, or where one or both parties is a very young minor, or where the parties are of the same sex. None of those forms of marriage even comes close to meeting the Court's standard for fundamental rights.
That's why Justice Kennedy has had to be so creative (some would say disingenuous) with the Constitution in the three "gay" decisions he's authored: Romer v. Evans in 1996; Lawrence v. Texas in 2003; and U.S. v. Windsor last year. I won't go into all the details here. But if you study those three decisions, you can see the bizarre rationale he has been developing, which the Court is probably planning to use when it some day declares a constitutional right to same-sex marriage.
Romer, Lawrence, and Windsor all turned on the Court's belief that the only possible motive for the laws in question was animosity--a "bare desire to harm"--homosexuals. Now, even if a law doesn't infringe any fundamental right--which would make it subject to "strict scrutiny," a very demanding constitutional test--it still has to at least be "reasonably related" to some "legitimate government interest" to be constitutional. But harming a group of people can never be a legitimate purpose of government. So if the Court thinks that's the only conceivable reason for a law, it will hold that law unconstitutional.
I can already see the would-be incestuous adult couples arguing, once same-sex marriage has been proclaimed the newest constitutional "right," that the only motive for excluding them from state marriage laws, too, is a "bare desire to harm" them. And how about the polygamists, who have historically been the target of all sorts of animosity and legal persecution in this country? Doesn't justice cry out for legalizing homosexual incest--or even incestuous homosexual polygamy?
And why should we get so uptight about age, either? Don't the NAMBLA people assure us their young cadets are fully consensual partners in sodomy, and that man-boy love is a beautiful thing? Shouldn't everyone be able to force all those Ozzie-and-Harriet squares in bourgeois America to put their seal of approval on his or her way of loving--even if it is a little different?
