In his five months of campaigning in behalf of the constitutional amendment that would give the District of Columbia voting rights in Congress, D.C. Del Walter E. Fauntroy has learned that what sings in Sheboygan may sound off-key in Oshkosh.

The problem -- how to promote ratification of the amendment before divergent interest groups -- gave Fauntroy some frustrating moments this weekend in Wisconsin.

So he responded in an age-old tradition of politicians: He told each audience what it wanted to hear.

Testifying before a committee of the Wisconsin state Senate here Friday afternoon, Fauntroy urged its members to "rise above narrow self-interest" and ratify the amendment because "some things (are) more precious in our system of government than race or region or party or special interest."

Later that day in Milwaukee, before an audience made up predominantly of black urban Democrats, Fauntroy said ratification is an extension of the civil rights movement and vital to the work of the black caucus.

Amid "amens" of agreement, Fauntroy added, "I didn't come here to preach. I came here because there is something wrong with my representation in Congress. I can't vote."

Milwaukee Mayor Henry W. Maier told the same group that ratification would make Washington "our first city-state, a much stronger voice for urban America... Who will speak for the cities if not us?" Maier said. "Certainly not the suburbs or the rural areas. We cannot afford to stand mute."

"We're selling this as a city issue, not civil rights," said the Rev. Roy B. Nabors, pastor of the Community Baptist Church of Greater Milwaukee, who had invited Fauntroy to be the main speaker at the church's community day banquet in the grand ballroom of the Phister Hotel.

Fauntroy and other boosters of ratification have little control over what people say about why they support -- or oppose -- the amendment, which give the District two senators and at least one House member. But as the issue is debated in state after state, the most outspoken, well-meaning advocates in variably are the people who opponents contend will be the primary beneficiaries of ratification -- urban, liberal, black Democrats.

It apparently was recognition of those realities that led legislatures in North Dakota and Wyoming last week to overwhelmingly reject ratification.

But based on the enthusiastic reception Fauntaoy got in Milwaukee -- the black president of the City Council introduced his as "the first U.S. senator from the District of Columbia? -- it may be expecting too much of any politician to urge caution and restraint from such an audience.

Nabors proudly reported to Fauntroy that nearly all of the 29 Milwaukee caucus members in the Wisconsin legislature are committed to ratification.

One who isn't however, is state Sen. David G. Berger (D-Milwaukee) who testified after Fauntroy at the hearing here.

Berger, who is generally regarded as a liberal by his legislative colleagues accused Fauntroy of offering testimony "charged with catch phrases... designed to paint opponents as those with narrow self-interests who wish to deny rights to others.

"That's unfair," Berger said. "I'm not here to deny rights. My conscience is clear."

Berger said he opposes the amendment "in its current form." He suggested that Congress start over again and adopt one of three alternatives -- statehood, retrocession of the District of Maryland or Virginia or representation in the House only.

As for Fauntroy's argument that District residents are entitled to voting representation because they pay $1.4 billion annually in federal income taxes, a figure that on a per capita basis is $327 above the national average, Berger said, "Those are clever figures. That's because your incomes are so much higher than ours. The congressman's salary is $57,000 and mine is $20,000."

"Oh my," Fauntroy moanded from the sidelines.

Berger went on to say that Washington already gets more than its fair share of federal help.

"There are few federal dollars in Milwaukee County Stadium or the Milwaukee Arts Center, but your money and mine built RFK Stadium and the Kennedy Center." he told his fellow senators.

Berger was carrying one of the blue spiral notebooks that have been sent to all 7,000 legislators in the country by the American Legislative Exchange Council (ALEC), an organization of conservative state legislators that is leading the nationwide campaign against ratification.

"Those were all good ALEC arguments," Fauntroy grumbled. "I'd like to know where they're getting the money."

Fauntroy is not alone in his anger about the ALEC campaign. Wisconsin Assembly Speaker Jim Wahner showed Fauntroy a copy of a letter he wrote to ALEC's executive director, Arizona Republican legislator Donna Carlson, complaining that the unsolicited briefing book "seems unethical." Wahner said that while it is being distributed "in the guise of being neither pro or con" ALEC "either did a poor job of research or selected material with little attempt at balance."

Fauntroy acknowledged that efforts by pro-amendment forces to raise money are floundering. He said a fund-raiser scheduled for Tuesday night in Washington is on the verge of falling on its face because its sponsors are "going about this in the wrong way."

Fauntroy wants the national ratification coalition to adopt a firm budget and "set out to get big gifts, the corporate donors" to finance it.

Dave Markham, an aide to a sympathetic legislator here, asked Fauntroy, "Who pays for a trip like this?"

"I'm disappointed but proud to tell you I do," Fauntroy answered. Later, Fauntroy said he hoped that the unspecified honorarium he would get from the Milwaukee speech would not only cover expenses for his trip here, but also would pay for trips earlier this month by members of his congressional staff to Missouri and North Dakota.