If you plan to become a political candidate, it can be enormously helpful if you are already a rich person. First, rich persons are often on a first-name basis with other rich persons, the kind capable of helping underwrite a big-bucks campaign. Even more important, personal wealth can magically bestow upon the candidate with it the priceless presumption of personal honesty. This is the Rich Don't Need to Raid The Petty Cash rule of electing people.

But in addition to pretty presumptions concerning the rich in politics, there are a few ugly stereotypes. Can the rich pol have any idea what it's like to live from paycheck to paycheck? Can a graduate of the best private schools and the best tennis camps whose life has been lived in a home with its own private security system understand the dependence of most Americans on the quality of public schools, the availability of public recreation and the safety provided by a public police force? Didn't the rich mostly get that way, asks the cynic, because they're greedy? This may help explain why Democrats, traditionally searching for status and respectability, have been more willing to give their nominations to the rich or well-born -- Roosevelt, Stevenson, Kennedy -- than have Republicans who never really accepted Nelson Rockefeller.

This brings us to the current problem of Republican presidential candidate and former Delaware governor Pierre S. (''call me 'Pete' '') Dupont IV. Late last month in Vermont, Dupont, the richest candidate this year in either party, joined three relatives in appealing a probate judge's decision awarding $1.5 million in a Dupont aunt's estate to four charities instead of to Pete Dupont and his relatives. The four charities on the other side are the Boys Club of Waterbury, Conn.; the Waterbury Hospital, the Waterbury Foundation and the Bennington County (Vt.) Humane Society. To Ed Rollins, manager of President Reagan's 1984 landslide and a 1988 strategist for Jack Kemp, Dupont has shown himself to be insensitive to the public consequences of a personal decision. ''Pete's a good guy,'' begins Rollins, ''but he doesn't understand that the average guy identifies more with the Boys Club than with millionaires.'' Cracks another well-known Republican: ''After all, it isn't as though the aunt left her estate to her cat.''

But Dupont campaign deputy Bob Perkins argues that the law is on the family's side, that payments from the estate to the nephew and nieces actually began in 1985 before lawyers for the charities went to court. Asked why the candidate didn't discreetly let his relatives carry the appeal, Perkins answers, ''Pete is secure. He's proud of his family and heritage.''

This sort of personal security which comes from being a Dupont in Delaware may be unique if insulating. You can forget about the Lees of Virginia or the Tafts of Ohio; no other state has ever been dominated by any family the way Delaware has by the Duponts. The real genius of the family was Pierre S. Dupont, the candidate's namesake, who demanded a 50 percent cash deposit from the Allies during World War I before he sold them $1 billion worth of ammunition. He then used the profits to secure control of General Motors.

Before all of this, Pete Dupont had broken more stereotypes than he had confirmed. As governor, he broke with the family and the company over a tough environmental law. In a campaign undistinguished for fresh thinking, Dupont has confronted big, controversial problems by proposing big, controversial solutions. In Iowa, he calls for an end to all farm subsidies. He would replace welfare with compulsory work at 90 percent of the minimum wage and give citizens the option of putting their Social Security contributions into an individual retirement account.

But in presidential politics, symbols count for much. They could even count Pete Dupont out if he were to be matched against Mario Generali, 62, of Waterbury. For 43 years in that city and for 20 years at the Boys Club, Mario Generali has been working with kids. ''Our Boys Club bus goes out to the {housing} projects every day. We bring kids who are having trouble, who can't afford it, in to be tutored. They play sports. Our budget is $240,000 a year.'' Personal acts do have political consequences.