While the Republicans in Detroit prepared to name their presidential candidate in a burst of pageantry, a baker's dozen of the lesser-known aspirants to the nation's top job were huddled here today in obscurity.

And that, they say, is their problem in a nutshell.

In a weekend session at Faneuil Hall, where the disenfranchised of an earlier era plotted revolution, 13 fringe candidates from around the nation embraced the rallying cry of that renowned American, Rodney Dangerfield -- "We don't get no respect" -- and voted to file a class-action lawsuit charging that federal election and communication law discriminates against them.

The 1971 federal election law disqualifies candidates who have not raised $5,000, complained the mostly insolvent presidential hopefuls gathered here. And that means broadcasters may snub their requests for equal time with the major party competition.

The 13 candidates, a diverse smattering of the 230 Americans seeking the White House post, blamed their political misfortunes on a refusal by the media to pay attention to their unorthodox campaigns.

"John Anderson thinks being an independent is tough," said John Graham, 65, an ex-Salvation Army officer and Little People's Party standard-bearer from Fort Smith, Ark. "Well, I can't even send the local Times-Record a press release without them throwing it in the wastebasket."

"The two-party system has railroaded us out of this election," said David Lester Hornberger, a lithographer and presidential candidate from Manhattan Beach, Calif., who wants the Nov. 4 election called off until every contender's name is listed on state ballots nationwide.

Hornberger plans to solicit the support of other minor candidates to serve as plaintiffs in the federal lawsuit.

The Constitution, said Hornberger, has been perverted by the Democrats and Republicans who comprise the Federal Election Commission. He notes the founding fathers' only stipulations for a presidential bid were that a candidate must be at least 35 years old, native-born and a resident for 14 years or more.

Said Nathaniel Denman, the group's non-lawyer legal counsel: "If the 1971 election law were in effect in 1856, Abraham Lincoln never would have become president and the Republican Party never would have gotten big enough to fill the convention hall in Detroit this week."

The would-be presidents said the solution lies in the hands of America's daily newspapers, which they feel should devote a few pages on any Sunday during the campaign to listing each candidate with a photograph, blurb and telephone number.

The candidates at one point converted the gathering into a forum for their individual campaigns. Each aspirant was given several minutes to speak before an apparently befuddled cluster of tourists who walked into the political session.

C. T. (Princess Running Water) Rockefeller, 64, from Covington, Ky., who is half of the only married couple aspiring to the presidency and who claims to have campaigned for four years longer than Harold Stassen, is running on a dual-plank platform: legalized gambling and 24-hour library service.

Robert DeJohn, 34, of Upper Darby, Pa., the presidential candidate of the Veterans Preservationist Movement says the Capital should be moved back to Philadelphia to "clear the air of the stench of Washington politics." b

Robert Roosevelt, 70, of Silver Spring, Md., is running to awaken America to what he terms a massive political conspiracy. Roosevelt believes several top politicians are actually under-aged and are using scientific methods to appear older. Others, he says, are foreign-born infiltrators.

Donald Badgley, 61, of Poughkeepsie, N.Y., became a candidate at the behest of heaven, he said. Badgely abstains from all coalition votes because, he said, "I don't believe in the legal system."

Hornberger, who wants to make marijuana a national cash crop and legalize prostitution, maintains: "We're not wackos; we're quite sincere. Some of our ideas might be considered weird, but who are we to judge? Let the American voters judge."

Postscript: At the risk of consigning some presidential contenders forever to the depths of obscurity, only six of the 13 candidates meeting in Boston appear in this report.