By now the old cars have gone to the automobile graveyards, carrying with them the bumper stickers, "Don't blame me, I'm from Massachusetts."

The college students who heard George McGovern announce that he will run again for president were barely in grammar school during the season of 1972.

To them and to the press in the room at George Washington University last week, McGovern was the man who had once been a "contendah." He lost the Democratic nomination to Hubert Humphrey in 1968, lost the election to Richard Nixon in 1972 (when he carried only Massachusetts and the District of Columbia), lost his Senate seat in 1980, and now he is trying to get back in the ring again, to win the title as comeback kid of 1984.

It's no wonder that while the other Democratic candidates worry about money and strategy, George McGovern's first priority is not to appear ridiculous. The one reason he hesitated to run for president was, as he told The Post, "the fear of ridicule . . . the fear of just looking like a Don Quixote and a kind of you know, 'Jesus! Not George again.'"

The press asked him what they asked each other. Wasn't he afraid of being "Stassenized," turned into a perennial candidate like that other contender until he was his own and only camp follower? Even his daughter, Mary McGovern, admitted, "There were concerns he might get hurt again." And a former aide said of this candidacy, "It makes a lot of us very uncomfortable."

This is the thing, of course. The man McGovern may be articulate, cool, sensible. But the candidate McGovern engenders some familiar anxiety.

I suppose it's the same anxiety that we feel when a former star, rusty and with a recent string of bad reviews, steps up to hit a ball or a note. We don't know if he'll make it. We hold our breath, hoping that we won't have to witness his humiliation, and wishing that he'd never tried.

None of us knows precisely the moment when someone who has lost a few will finally become a loser. At what point do we wish that a batter in a slump wouldn't even get up to the plate anymore? When does someone who once gathered attention begin to garner embarrassment?

It's hard enough to assess and accept the slippage in our own skills and powers. We all hope we'll be aware when it's our time to go, whether we're leaving the stage or the field or a job or a relationship. But it's particularly painful to see others, slipping and scrambling, hoping for the big comeback. We are embarrassed when we witness people lusting after the things that have passed them by, whether those "things" are youth or looks or power.

For every Carl Yastrzemski, still hitting the fast ones at 44, there is a Willie Mays, hanging on and on. There are few Margot Fonteyns who are able to dance through mid-life. We breathe more easily when a Beverly Sills moves on from opera singer to director, before her voice gives out.

As for politicians, especially defeated politicians, it's much easier for followers to see Henry Wallace retire to his agricultural experiments at Farvue Farm than watch Harold Stassen be a compulsive candidate.

We prefer elder statesmen to elder fools. We never want to feel sorry for our heroes.

Is it preordained that McGovern will become ridiculous? No. He has it in his hands to retain as much--or as little-- dignity in this campaign as any of the other candidates. But the odds are against him.

What we have is a platform built on "reason and common sense" and the hope that "lightning will strike." We have the candidacy of a 61-year-old man who was, simply, restless in retirement. "I'm not doing this just for the exercise," said McGovern, but in fact he is again making tracks toward the lights, the camera, the stage.

Against the advice of friends and family, without a campaign manager or a full-time fund-raiser or any measurable constituency urging him on, the South Dakotan is running for president because, "You have to do what you have to do, and I have to do this."

There is the risk that we will be the audience for one of those sad farewell tours starring the man who was the main contender of 1972. That, as his aide said, makes a lot of us uncomfortable..