Unfortunately, the Court does not restrict itself to simply upholding or overturning laws.
In Everson vs Board of Education (1947), the Court upheld the constitutionality of using public funds to bus parochial school students. But in the process, it inserted this gratuitous statement: “The First Amendment has erected a high wall between church and state. That wall must be kept high and impregnable.” But the first amendment says nothing about a wall. It protects religious liberty. This was one of the first steps in turning the First Amendment on its head. That statement was then used in future cases to make bad law.
In Engle vs Vitale, (1962), the Court struck down this voluntary prayer used in a public school:
“Almighty God, we acknowledge our dependence on thee, and we beg thy blessings upon us, our parents, our teachers, and our country. Amen.”
The prayer is pretty innocuous, and I doubt that generations of previous jurists would have found anything objectionable about it, but the Court had by now decided that God must be at all costs ejected from public schools. Twenty-two states had filed an amicus curiae brief urging the upholding of the prayer.
Griswold v Connecticut (1965) overturned a state law prohibiting the sale of contraceptives. It’s basis was that the law violated the “right to marital privacy.” Now, no right to privacy could be found anywhere in the Constitution. No matter. The Court created that right ex nihilo. Justice Hugo Black, in his dissent, noted that the Constitution contained no right to privacy anywhere. Justice Stewart in his dissent, called the Connecticut law “uncommonly silly” but certainly not unconstitutional.
The right to privacy, previously created ex nihilo in Griswold, was used to justify overturning abortion laws in Roe v Wade. It’s companion case Doe v Bolton, effectively made abortion legal anytime throughout pregnancy, a more liberal abortion law than any state or any nation. Who knew that was in the Constitution? Certainly not those who wrote it.
In Roberts v Madigan, (1990) the Court ruled that it was unconstitutional for a public school teacher to be seen with a personal copy of a bible on school property. Hmm, is that not an interference with his free exercise of religion, something which is guaranteed by the First Amendment?
In Lawrence v Texas, (2003) the Court found a right to sodomy within the Constitution. It seems to have taken awhile to find that right in the Constitution, but now it might well form the basis for gay marriage.
Most famous of all, in Planned Parenthood v Casey (the Casey here is the former pro-life Governor Bob Casey of Illinois, who was denied the ability to speak at the Democratic Convention), the court not only upheld abortion as a constitutional right, but made the following observation:
“At the heart of liberty is the right to define one’s own concept of existence, of meaning, of the universe, and of the mystery of human life.”
Now, I can imagine Ben Franklin, John Adams, Thomas Jefferson, and a good many others gathered around, and let’s say one of them came up with that statement. I can picture the puzzled looks, and the response, “What in heaven’s name are you talking about?” Or perhaps Jefferson might have said “What in the name of Zeus are you talking about?” Because even he wasn’t a total relativist. They didn’t believe that their words were just a bunch of mush to be manipulated at will.
I rather like their unpredictibility. But, regardless they are what we have and their opinion is the only one that counts on decisions. 
