A group of aggrieved Wisconsin Democrats, led by Gov. Anthony S. Earl, appealed to a national party panel today to respect their state's idiosyncratic political culture by permitting them to resume holding a presidential primary open to independents and Republicans as well as Democrats.

A closed -- or Democrats-only -- primary system, which the Democratic National Committee (DNC) forced on Wisconsin last year, "disenfranchises a lot of people whom we ought to be reaching out to . . .[such as] independent voters, who are the best test of whether the candidate can pass muster in the general election," said Joseph Sensenbrenner, mayor of Madison.

His testimony came before a regional hearing of the DNC's Fairness Commission, charged with reviewing the party's nomination rules for 1988.

The national party adopted the closed primary rule in 1972 to keep Republicans from crossing over and casting "mischievous" votes that might skew the Democratic result.

Wisconsin, which does not have registration by party, has long been a state where voters treat their partisan affiliation as "none of your damn business," Earl said. It won exemptions from the rule through 1980, but the DNC insisted on compliance in 1984.

The result was a two-part nomination process last year that produced a split result and delivered a "slap in the face" at most Wisconsin Democrats, according to state Attorney General Bronson C. LaFollette.

Sen. Gary Hart (D-Colo.) won the state's nonbinding open primary, while former vice president Walter F. Mondale won the closed caucuses, which were conducted on a different day and attended by one-twentieth the number of voters.

The Wisconsin speakers were challenged today by commission member Morley Winograd of Michigan, who argued that nominating a presidential candidate is party's most important business and therefore should be a members-only affair.

Earl countered with a resolution, unanimously adopted earlier this week by the nation's Democratic governors, that said the delegate selection process should "accommodate the variety" of state political cultures so long as it does not sacrifice "fundamental Democratic principles." States rights has become a rallying cry this year for a broad array of party activists who believe the DNC has overregulated the nominating process in the past 15 years.

"I think we have a chance to get this changed," Earl said after the hearing. "I sense that [DNC Chairman Paul G.] Kirk is more sympathetic than [former DNC chairman Charles T.] Manatt was."

The commission, which is holding four regional hearings this month, is the fifth body of its kind to come into being since the party went on a rules-change kick following the 1968 convention.

Unlike its predecessors, this panel has a charge to tinker, not overhaul. "We don't want to reinvent the wheel," Kirk said in June as he convened the body and told its 51 members to complete their work by the end of the year.

At today's hearing, several Iowans used the Kirk message to argue for preservation of their state's first-in-the-nation caucus. "We have more important things to do than change the calendar again," said state chairman Art Davis.

But the Iowa caucus and New Hampshire primary were lambasted by Michigan Sen. Carl Levin (D), who accused the two states of "holding the party hostage" every four years to guarantee their continued "disproportionate" impact on the process.