We in the media habitually describe the Supreme Court as made up of four conservatives, four liberals and one swing-voting centrist, Anthony Kennedy. These labels serve reasonably well to situate the justices on the ideological spectrum compared with one another.

But while the court is sometimes called "conservative," it looks pretty liberal if we chart the justices' rulings and individual views against general public opinion, as measured by poll results on issues including abortion, race, national security, religion, gay rights, gun rights and the death penalty.

The four more liberal justices -- John Paul Stevens, David Souter, Ruth Bader Ginsburg and Stephen Breyer -- all fall markedly to the left of public opinion on every one of the abovementioned issues. So does Kennedy, when it comes to national security, religion, gay rights, the death penalty and to some extent abortion. Judge Sonia Sotomayor is widely expected to be at least as liberal as Souter, whom she would replace.

If President Obama gets an opportunity to replace one of the five more conservative justices, the new majority will be quite dramatically to the left of public opinion. And voters will, of course, remain powerless to overturn the justices' constitutional interpretations.

Justices Antonin Scalia and Clarence Thomas fall markedly to the right of center. But the same does not appear to be true -- not yet, at least -- of Chief Justice John Roberts and Justice Samuel Alito.

Indeed, while those two George W. Bush appointees appear to be politically conservative by some measures, the description of them as far right by the New York Times editorial page says more about the editorialists than about the justices. So far, Roberts' and Alito's opinions and votes have been considerably closer to the center than those of the four liberals.