Both of the men running for president displayed their shortcomings yesterday in reacting to the Supreme Court’s ruling that the Second Amendment includes an individual right to keep a handgun at home for self-defense. The amendments at stake include not only the Second but also the First and the 14th, so even those who aren’t handgun enthusiasts or partisans of gun control will want to pay attention.

Senator Obama’s statement was the more astounding one, if only because it came from a professor of constitutional law and a former editor of the Harvard Law Review. It’s hard to know where to begin. First was the audacity of Mr. Obama appearing to praise the court’s finding that the Second Amendment right to bear arms applies to individuals and not only to militias. The ruling was made by a five to four margin, and two of the justices in the majority — the chief and Justice Alito — wouldn’t be on the federal high court at all if Senator Obama had gotten his way during their confirmation hearings. Senator McCain voted to confirm both, while Mr. Obama voted against them. Should Justice Kennedy, 71, or Justice Scalia, 72, decide to retire in the next four years, there’s little reason to think that a President Obama would fill the vacancy with a judge who would protect gun rights.

Then was Mr. Obama’s statement, in respect of gun rights, “I know that what works in Chicago may not work in Cheyenne.” It is true that our federal system gives state and local governments the ability to adjust policies to suit regional differences. But the federal courts have read the due process and equal protection clauses of the 14th Amendment, which was adopted in 1868 after the Civil War, to restrict the state and local governments from infringing on the rights enshrined in the federal Constitution. Imagine the fuss that would be put up by NARAL, for example, were Senator McCain to suggest that what works in New York as far as abortion rights may not work in Alabama. Or by the NAACP — and rightfully so — were Mr. McCain to suggest that what works in the North as far as integrated education doesn’t work in the South. Do the people of Chicago not deserve as full a Bill of Rights as those in Cheyenne? If Mr. Obama truly believes that gun laws should be left to the states and local governments, the intellectually honest position would be to favor repeal of the Second Amendment.

Meanwhile, Senator McCain greeted the decision with a statement that said, “today’s ruling recognizes that gun ownership is an important right — sacred, just as the right to free speech and assembly.” If Mr. McCain really believes the right to free speech is “sacred,” why has he devoted so much time and energy in his congressional career to imposing new restrictions on campaign speech under the rubric of campaign finance “reform”? Given all that Mr. McCain has done to shred the First Amendment with the McCain-Feingold law restricting the airing of television commercials mentioning candidates’ names within 30 days of a primary or 60 days of a general election, his claim that he finds gun rights as “sacred” as “free speech” is entirely unreassuring.

There are plenty of swing voters in swing states such as Pennsylvania and Ohio who own guns and would like to know that their Constitutional right to do so will be safe four years from now, regardless of who leaves the Supreme Court and who joins.

And they have reason to be worried. Their civil rights yesterday were upheld by only the narrowest of margins. A single vote. The liberal wing of the court — encompassing Justices Ginsburg, Stevens, Souter, and Breyer — looked hard at the Second Amendment, and found that the Amendment doesn’t protect the rights of ordinary gun owners. It took the conservative wing of the court — Chief Justice Roberts and Justices Scalia, Thomas, and Alito — joined by swing vote, Justice Kennedy, to see this as a civil rights issue and to rule accordingly.

If ever a precedent were in peril, this is the one. The Supreme Court will no doubt hear a series of cases in the coming years challenging various gun laws, including perhaps those of our own city of New York. One reassurance as far as Mr. McCain goes is that President Bush, who signed McCain-Feingold into law, also nominated the justices, Roberts and Alito, who made yesterday’s majority ruling possible. The Second Amendment was adopted in 1791. Which may yet itself be the greatest reassurance, that we have a government not only of individuals with human frailties but of laws that have a way of outlasting both the judges and the politicians.