Late Tuesday night, Sen. Edward Kennedy called former vice president Walter Mondale at home. Recalling Mondale's well-publicized campaign appearance with him this fall in behalf of Kennedy's reelection, the Massachusetts Democrat began the conversation with a quip: "You did such a spectacular job in Boston that I've decided to withdraw."

More important than how Mondale got the information that Kennedy would not run in 1984 was what he did with it over the next 24 hours. His actions, contrasted to how his potential 1984 opponents reacted, shows why Mondale must now be considered the nation's leading presidential candidate. He showed both personal sensitivity and political shrewdness, while the rest of the field, most conspicuously Ohio Sen. John Glenn, showed precious little of either.

Understanding that the day belonged to Kennedy and his supporters, Mondale, after issuing a generous statement warmly praising Kennedy, refused to be drawn into the idle and almost-ghoulish speculation about whose candidacy would be most helped by Kennedy's absence. Others were not so disciplined or thoughtful, and each candidate, real or imagined, miraculously managed to reach the same conclusion, viz., that his own candidacy would benefit most directly from Ted Kennedy's non-entry. There was John Glenn on the evening news, from the Senate TV gallery, where he had gone voluntarily, handicapping the race. If Glenn had asked him, George Bush could have told him after Bush's 1980 post-Iowa gushing about "momentum" that election analysis is not high on most voters' job description for their president.

What Mondale seemed by his actions and restraint to grasp is that while many people are intrigued by Kennedy's actions, only Kennedy voters and supporters, of whom there are a whole lot in the Democratic Party, were genuinely touched by the Wednesday announcement. Imagine yourself a Kennedy volunteer, devastated by your leader's withdrawal. You turn on the news to hear what your party's leading figures have to say about your man and all they talk about is how his leaving affects them and their ambitions. All, that is, except the former vice president. Whom in that large field would you now feel most warmly toward?

Glenn was not alone. Former president Jimmy Carter, who has lately been on more talk shows than Dr. Joyce Brothers, disclosed to a breathless nation that he, Carter, would not be a 1984 candidate.

Mondale, prior to Wednesday, was the beneficiary of Kennedy's candidacy in that he had the support of many Democrats who dreaded a Kennedy nomination. Now the specter of a Kennedy candidacy will no longer help him. But by his sensitivity and restraint, he has helped give himself as good a shot as anyone at the Kennedy constituency. First round to Mondale.