If chutzpah were silver, David Garth would be Nelson Bunker Hunt. And the price of that metal would not dare to drop a dime.

Garth, still unmellow and now unfat at 50, is the driven and successful political campaign consultant who may play a very large part in determining whether John Anderson is the Teddy Roosevelt or the Henry Wallace of 1980.

From his Fifth Avenue offices, it's only a good cab ride in just about any direction before you start running into Garth winners now in public office: Mayor Ed Koch and City Council President Carol Bellamy in New York; Govs. Hugh Carey in Albany, Brendan Byrne in Trenton and Ella Grasso in Hartford; Philadelphia Mayor Bill Green and Pennsylvania Sen. John Heinz. All of them have occasionally sworn at and, most of the time, sworn by brassy David Garth.

But in April of this presidential year, John Anderson of Rockford and David Garth of Manhattan are a very hot political couple with the capacity between them to make either a large political difference or a really big personal disaster in the next few months.

What Garth brings to the persistently didactic and periodically dogmatic Anderson is, most of all, *igravitas*n. Garth is too aggressive and can be too domineering, but he is a serious political person. His commitment to his candidates is legendary. He does not hesitate to call at midnight reporters who, in his undetached judgment, have ignored or insulted his candidates in print. He knows that there are very few brilliant strategies in politics, but that thorough preparation frequently passes for brilliant strategy.

That is why, although he would not admit it, Garth was undoubtedly rooting for George Bush and Edward Kennedy to win in Pennsylvania last Tuesday. Garth, the professional realist, knows that those two upsets will probably not prevent the nomination of either Jimmy Carter or Ronald Reagan. But he knows now that the front-runners' agony will be prolonged and the chances of their making mistakes, mistakes that Anderson could exploit in the fall, will increase. Most important, the Pennsylvania results meant several more weeks out of the spotlight for Anderson and his infant independent candidacy -- time to organize, to train petition-circulators, to obtain the signatures, to qualify for the general election ballots in as close to 50 states as possible.

Garth knows that, for John Anderson to be a true challenger for the presidency, he cannot be either a "spoiler" or simply the favorite of the brie-and-chablis set. Garth has nothing personal against natural foods or brown rice, but he believes that a lot more voters stock Hamburger Helper. A "spoiler" is someone with no serious chance of winning. Spoilers fail to qualify for enough state ballots (as Anderson failed in Pennsylvania) or they avoid the prevailing campaign dialogue, preferring to make their own statements of conscience about the "real, overlooked issues." Garth's candidates do not disregard a campaign's dialogue; they frequently dominate it. c

A real candidate, in addition to getting his name on the ballot, must have a real vice-presidential candidate, not a series of local stand-ins. A real candidate has a law firm, preferably a high-powered one, challenging state laws that were written to keep people like him off ballots. A real candidate demonstrates the capacity, which all citizens understand and all politicians respect, to raise adequate funds to run a national campaign.

Garth is urging all these courses of action upon the Anderson campaign. If all of these tasks can be performed in the next 90 days, then the campaign will have achieved what Garth calls "viability." He is less concerned about what he calls the "credibility" of the candidate; he is confident that Anderson can persuasively make the public case for his credentials and effectively define the differences between him and Reagan and Carter.

David Garth has long been comfortable with long shots. In 1960, as a rebellious 30-year-old, he organized the demonstrations inside and outside the Los Angeles convention for Adlai Stevenson. In 1978, he masterminded Hugh Carey's remarkable comeback victory from a negative job rating of 70-30. He has come back a political winner in states as diverse as California, West Virginia, Illinois and Ohio.

Both of these strong-minded individuals will be in for some stormy times together. But if they work out their differences and manage to work together, by Halloween Anderson and Garth, a real odd couple, could be making a very big difference in American politics.