Whew! What a relief. The candidate of new ideas -- or the only ideas, to hear him modestly tell it -- and idealism, too, has returned.

It's about time, too. The country badly needs reassurance. As Gary Hart wisely says, there are lots of problems out there. Among them are arms control, deficit reduction, the stock-market crash, quality of education, quality and kinds of jobs, the falling dollar, trade imbalances, lack of U.S. competitiveness, how to deal with Gorby, what to do about the contras.

So give thanks to Gary, fellow Americans, for offering to save us and put those great new ideas into practice.

Don't be so churlish as to ask: What great new ideas? And don't be so cynical as to think: Sure, Hart's back because he's deep in debt. Reentering the presidential race gives him a chance to repay old campaign bills by dipping into the federal till and being given matching campaign funds, courtesy of the taxpayers.

No, take him on faith, and at face value, and here's what you get:A candidate who should not win and will not win unless American voters have taken total leave of their senses.

Hart's character, judgment and behavior are all a matter of public record, and each should disqualify him for the presidency. In every elective office, public trust is the one absolute, indispensable ingredient. That is infinitely more so in the presidency with its life-and-death powers that citizens grant to a chief executive. On trustworthiness alone, Hart is a failure.

A candidate capable of becoming a great spoiler in a Democratic field fragmented and overpopulated.

Hart's return is the best news for the Republicans, some say, because it immediately throws the Democratic race into disarray, adding greater uncertainty among and about the candidates and reinforcing the notion that none of them possesses presidential stature. I think that view is false but that Hart clearly intends to exploit it for his own advantage.

A candidate likely to produce even more cynicism among jaded American voters. This, after all, is the same Hart whose reckless actions left many of his most ardent supporters and key members of his political and personal staff rightly feeling betrayed. His reentry instantly becomes the stuff of farce, the grist for "Saturday Night Live" parodies and endless new salacious Gary Hart stories.

Here, "new ideas" aside, is what he has going for him:The perversity of primary politics.

Previous campaigns have demonstrated that, in primaries, voters feel free to vote their prejudices in ways that they will not do in the actual presidential balloting.

The most vivid example of this was in the 1968 presidential primary campaigning of Alabama's George Wallace. Then, the same people who said they were voting for Wallace in the primaries to "send 'em a message" also said they would never support him in a presidential election. They considered it all right, even desirable, to register extreme racial resentment and anger about dictates of Washington in the primaries. It was not right to do so in the presidential contest. They implicitly recognized that, in the best interest of the nation, a president must be above narrow partisanship and prejudices.

Hart's greatest appeal, thus, could lie in his ability to get Democratic primary voters, especially in New Hampshire, to express a 1988 version of "send 'em a message." That message would be: None of the above. Such a result would further imperil next year's Democratic presidential prospects.

Public disgust with big-media and big-bucks political manipulators, most of whom are seen as residing in Washington.

Resentment against perceived news media destructiveness and hypocrisy has intensified in the months since Hart's withdrawal from the presidential contest. I hear it expressed everywhere and by a range of Americans from college presidents to farmers. The idea that the media "got" Gary Hart and others in public life is repeatedly articulated. That Gary Hart got Gary Hart just as Richard M. Nixon got Richard M. Nixon does not satisfy media critics.

Hart's return raises another possibility -- redemption.

Perhaps Hart has learned a lesson and earned a chance at a new beginning. If so, he could employ as a campaign slogan the explanation given by Donna Rice's employers when she was dismissed from her modeling job. "We are moving into a new year and a new image," a spokesman said, in announcing Rice's dismissal on the same day that Hart reentered the race.

There's a new idea. Run with it, Gary.