Like many Americans, we have been intrigued and often exasperated by the long-running Democratic primary and the ever smaller-bore spats between Senators Hillary Clinton and Barack Obama. So we are thankful to Senator John McCain for reminding us Tuesday what this year's presidential race really is about.

On a day when Mr. Obama won a decisive victory in North Carolina and Mrs. Clinton eked out a win in Indiana, Mr. McCain spoke about his judicial philosophy. He is determined to move a far too conservative and far too activist Supreme Court and federal judiciary even further and more actively to the right.

Mr. McCain predictably criticized liberal judges, vowed strict adherence to the Founders' views and promised to appoint more judges in the mold of Chief Justice John Roberts and Justice Samuel Alito. That is just what the country does not need.

Since President Bush chose Justices Roberts and Alito, the Court has ordered Seattle and Louisville to scrap voluntary school integration, protected employers who illegally mistreat their workers, and constrained women's right to choose and voters' right to vote.

Mr. McCain did not mention, of course, how the Roberts-led Court blithely overruled Congress by nullifying a key part of the McCain-Feingold campaign finance law. He did wax nostalgic about what "the basic right of property" has meant "since the founding of America." (He did not mention that in 1789 many women could not own property and African-Americans were property, but he did criticize the idea that values evolve over time.)

There was a moment when we were briefly cheered. Mr. McCain declared that "all the powers of the American presidency must serve the Constitution and thereby protect the people and their liberties." We hoped that would be the start of a serious critique of how President Bush has violated cherished civil liberties: endorsing torture, ordering unlawful domestic spying and depriving detainees of the most basic right of habeas corpus.

Mr. McCain himself has eloquently criticized Mr. Bush's policies on some of these issues, but he did not raise any of them on Tuesday.

Which brings us back to the Democratic primaries. Unless Mrs. Clinton decides to quit the race - and she certainly did not sound on Tuesday like that was her plan - it is going to be up to the superdelegates to settle this contest. There has already been a lot of discussion about how they should do so. Choose the candidate who won his or her state primary or caucus? Or the one with the most delegates? Or the most votes overall? Or the one who won the biggest states?

Mr. McCain's speech suggests an additional metric: the candidate best able to explain to voters in coming days what is truly at stake in this election and why the country cannot, for example, afford another president committed to packing the courts with activist, right wing judges.

There are few policy differences between Mrs. Clinton and Mr. Obama. But there is a vast gulf between Mr. McCain and the two Democrats - and far too little difference between Mr. McCain and President Bush.

Instead of sparring, pointlessly, about who first opposed Nafta or which of these Ivy League-educated lawyers has a more common touch, Mr. Obama and Mrs. Clinton should explain what they will do to restore the balance of power and protect civil liberties. They need to talk a lot more about addressing the health care crisis and the mortgage crisis and how they would bring American troops home and contain the chaos in Iraq.

Mrs. Clinton and Mr. Obama can continue to tear each other up and fight over each superdelegate, or they can debate the issues - for the sake of the voters.