Here at home, Sen. Paul E. Tsongas' surprise announcement that rightish Sen. John Glenn (D-Ohio) is his candidate for president has been received with contradictory reactions--that is, either utter disbelief or the certainty that the neo-liberal junior senator from Massachusetts is bidding for the vice-presidency.

"No one is saying what a marvelous idea it was," observes one bemused politician. "They're just asking why he did it."

Said a political science professor from Wellesley College, who was inhaling the heady air of John Kenneth Galbraith's annual Harvard commencement garden party, "I find it inexplicable."

A member of the Harvard faculty said, "So do I. I'm not saying Glenn couldn't win a general election, but can you imagine the man who killed SALT II beating Alan Cranston in the Massachusetts primary?"

Feeelings about the nuclear freeze run high in Cambridge. When Dr. Victor Weiskopf, in receiving an honorary doctorate, was cited for his opposition to the nuclear arms race, the entire audience rose in tribute.

Across the river in Boston, the political sharpies greeted the Tsongas surprise with the flat assertion that it was nothing but a crass bid for a place on the Glenn ticket, something which Tsongas vehemently denies.

"Paul is a very ambitious guy, and he knows Mondale can't have him because they're too much alike," one student of the game observed.

It was also explained in psychological terms. "Paul just has to be different," sighed a Boston politician, who for reasons of peace in the family wished his name withheld. "It's living with Teddy."

Coexistence with Sen. Edward M. Kennedy (D-Mass.) is somewhat like sharing a small kennel with a large and somewhat rambunctious Saint Bernard. It takes its toll, and sometimes Tsongas rebels--most notably in 1980, when at an Americans for Democratic Action meeting before the Democratic convention he demanded that the liberals change their ways.

"Paul has a conscience," said a House colleague from Massachusetts, "so he almost always votes right. But he so wishes he could be something other than a liberal. He's always trying to move to the right."

The Kennedy people, beginning with their leader, consider this to be Tsongas' most expensive declaration of independence, since he explained his choice by stating that he did not think "my values"--on which, of course, he will campaign for reelection to the Senate--"can win in 1984."

Tsongas mourns that former vice president Walter F. Mondale is his old friend and close neighbor in Cleveland Park, that Sen. Cranston's preoccupation with stopping the arms race mirrors his own concern. He says he was impelled into early action by the specter of Ronald Reagan "unleashed" in a second term.

Glenn's record on nuclear arms and defense spending, which makes him uncongenial to liberals, was a stumbling block for Tsongas. He was "angry for a year" at the Ohio senator for the hard line on verification which did so much to stop ratification of the strategic arms limitation treaty (SALT II). Glenn's opposition was based on the loss of the Iranian monitoring stations. Authoritative word from the Carter White House that the slack would be taken up by the Chinese was not enough for him.

Now, however reluctantly, Glenn is for the nuclear freeze, and against the MX. Tsongas figures that no president would be in a better position to win acceptance for nuclear accord with the Russians than the smiling former astronaut.

On the political level, the symmetry of pitting an authentic hero against a movie hero has great appeal for Tsongas. Also, Glenn personifies the traditional patriotic and family values which Reagan has preempted for the Republicans. Glenn is no "Democratic Eisenhower," according to his new and not exactly fanatical sponsor. Glenn's ideas for industrial renewal bear no resemblance to Republican laissez-faire reflexes.

"What ultimately counts," he says, summing up his reasons "is beating Reagan. Glenn has by far the best chance."

And four days later, to tell him that winning isn't everything, that issues count, too, came 2,000 caucusing Wisconsin Democrats, who, amazingly, chose Cranston of California over front-running Mondale. The Mondale people are quick to say they were "out-organized," which is a way of evading the real issue, their lack of the "intensity factor," dogged, single-minded Cranston's greatest strength.

Mondale lost out to a fine spring day--many of his delegates failed to show up. Freezeniks would come out in a blizzard for their cause.

The news from Milwaukee, where Glenn chose not to compete, tended to eclipse the opening to the left provided by Tsongas. Both surprises coming as they do at a moment while the lucky man in the White House goes merrily up in the polls, may in the long run do nothing more than remind the apathetic voters out there that it's awfully early in the Democrats' civil war.