GORE, Rockefeller, and Gephardt may be out of the presidential campaign, but 99 other Americans are already in the running for the White House.Records at the Federal Election Commission show a rapidly growing field of candidates - some serious, many not-so-serious - for the 1992 campaign. There are even two contenders for vice president (Watch out, Dan Quayle!). The official list includes well-known people, like former Sen. Paul Tsongas (D) of Massachusetts, and people who are virtually unknown, like Frank Barela III, a Republican from Phoenix, Ariz. Sen. Al Gore (D) of Tennessee, who took himself out of the running last week for family reasons, is just one of the big names to avoid a campaign against President Bush. The race also didn't look appealing to Sen. John D. Rockefeller IV of West Virginia or House majority leader Richard Gephardt of Missouri. Yet Mr. Bush's record popularity hasn't daunted some would-be presidents like Elijah Anderson Omega, an independent from Palmdale, Calif. Nor has it turned aside Lloyd O. (Alamo) Scott of Lubbock, Texas, who seems to be appealing to voters from both major parties with a campaign committee called "True Democrat-True Republican." There are a lot of Republicans in this race, like Aaron Wayne Sartain of Grandview, Mo., Norman A. Russ of Norwich, Conn., and Margaret S. Range of Birmingham, Ala. Perhaps they are all expecting George Bush to skip the 1992 election. Some of the candidates have an ideological message they want to get across. Mr. Barela's finance committee, for example, is called, "People's Revolutionary Continental Army." The Communist Party will have at least one entry. Under the party's heading, the FEC lists Benjamin F. Schoenfeld of Los Angeles, Calif. The number of candidates is actually smaller in this election cycle than in some previous years. Four years ago, about 300 people had sent official entry forms to the FEC in hopes of being the replacement for Ronald Reagan. Two of the candidates this year represent the Freedom of Choice Party. They are Jouett Edgar Arnez for president and Carl L. Kemp for vice president. If the entry form is correct, however, there may be a problem. Both come from Lansing, Kan. Yet the 12th Amendment to the United States Constitution forbids the election of a president and vice president from the same state. The FEC tries to sort all this out by dividing the entries into those who have received contributions or spent $5,000 or more (the ser ious contenders), or those who haven't (the not-so-serious contenders). Using that rule of thumb, there are six serious candidates so far this year. They are: Paul Tsongas, the only major Democratic candidate actually in the race, who has raised $507,000. L. Douglas Wilder, the Democratic governor of Virginia, who has raised nearly $120,000 to explore a possible White House campaign. Lenora Fulani of New York City, the 1988 New Alliance candidate, who has raised $141,000 toward the next campaign. Lyndon H. LaRouche Jr. of Round Hill, Va., who calls himself a Democrat but is shunned by mainstream Democrats, who has raised $94,157. Andre V. Marrou, a Libertarian from Las Vegas, Nev., who has raised $84,677. Richard Benjamin Boddie, a Libertarian from Huntington Beach, Calif., who has raised $18,226. The others have shown few signs of political activity, federal officials say. Of course, it's still not too late to enter. The cost, if you are interested, is just a 29-cent stamp. Rest assured your entry will be computerized, microfilmed, and then filed away for posterity. As one FEC official puts it, "The government never throws a piece of paper away."