Students of current events writing on Tuesday morning are expected to discover whether Mr. Obama or Mrs. Clinton is responsible for the collapse of the stock market. Because the accents in which they engaged each other on Monday night certainly asked the voters to conclude that the collapse of the stock market was the doing of one of them.

You may smile, but they are not smiling. It's true that political competitors, in a very hot race, become, well, unfriendly. When outgoing president Herbert Hoover suffered the indignity of having to ride in the same limousine with President Franklin Delano Roosevelt from the White House all the way to the Capitol, he made his feelings known during the seven-minute ride with the president. He did not open his mouth.

Well, that's the direction in which Clinton and Obama are headed. The New York Times writes that the "totality of the attacks" lays bare "the ill will and competitive ferocity that has been simmering between them for weeks."

When two antagonists are required by a scheduled event to speak to their opponent, and when it is clear that they would much rather tear out the eyes of their opponent, they tend to seize on a casus belli which you and I would not think all that mortal, if directed at you or me. Mrs. Clinton railed against Obama because, she said, he never acknowledged responsibility for legislative measures that he had voted for.

He fought back by charging that the Clintons spend all night every night combing through the 4,000 votes cast by Obama in the Illinois state legislature, looking for something to criticize. By contrast, he said, he had himself attempted to maintain "a certain credibility" in the race.

Well, that brought on a charge by Hillary that Barack was tied in with a slumlord in Chicago. In fact, early in his career he had worked for a law firm that did legal work for Antoin Rezko, but that was the sum total of that connection. During this season he has already returned $40,000 in political contributions that were linked to the alleged slumlord.

Obama came back by pointing out that Mrs. Clinton had served as a (paid) director of Wal-Mart from 1986 to 1992, while he was "working on the streets of Chicago" as a community organizer. Mrs. Clinton did not have much to say about that.

The animal spirits got so hot that before long, Barack was taking on not only Mrs. Clinton but Mr. Clinton. "I can't tell who I'm running against sometimes," he said, charging that Bill Clinton had done as much as his wife to distort Obama's views and record. At several points, Obama used the phrase "Senator Clinton and President Clinton."

Well, one of the two stands a very good chance of becoming president. And it can only be said with confidence about their current contentions that not a correction will be made, in 2009, when their differences will be taken as simple campaign oratory. That is how, after the 1940 election, Wendell Willkie characterized his observations about FDR, whom, during the campaign, he had said should be handcuffed, sent to Sing Sing, and deprived of bread and water.

All told, it seems a pretty conventional modern contest for power between candidates who wish to exceed each other in promises made to the voters. "Health care should be universal," said Hillary. Obama might have answered, "Success in the stock market should be universal." But there isn't anything a president can do to secure that, so if Obama wins, he'll have to settle for providing health care for Dow Jones.