It was south of here, about where the Wisconsin River joins the Mississippi. Jimmy Carter, normally the most private of public men, was in an expansive, almost exuberant mood, as he sat in his shirtsleeves on the Texas deck of the steamboat Delta Queen.

For almost an hour, he chatted with a handful of reporters around a wrought iron table. He talked about Mark Twain, the river, and how Joliet, the French explorer and fur merchant, lost his diaries and nearly his life when his canoe overturned near here in June 1673.

He talked about his brother Billy, his chief of staff Hamilton Jordan, and Washington lawyer Lloyd Cutler. He reminisced about "the good old days" and the practical jokes early in his administration. He talked about his own diary-keeping, and of such profundities as reading in the bathroom and at the dinner table.

When the subject of United Nationa Ambassador Andrew Young and the controversay around his resignation came up, Carter grew protective; his answers became short and clipped.

When reporters tried to press him, Carter fell silent. It was clear, those present said, that this was a subject he didn't want to talk about.

So it has been in the days since Young's resignation -- most of them spent aboard the good ship Delta Queen (Steamboat I, as it came to be called). Carter carefully managed to say as little as possible about Young, and nothing at all about the potentially explosive controversy between blacks and Jews that Young's resignation kindled.

It was as if the issue didn't exist at all.

And indeed, it was hard to see much urgency about it in places like Wabasha, Minn., Alma, Wis., or Keokuk, Iowa, as the steamboat churned downstream, and thousands turned out to greet the president and his family. "Here, the PLO and Israel don't mean anything," Rep. Harold L. Volkmer (D-Mo.) said in Hannibal, Mo.

When Carter opened himself to questions from the public during a radio call-in show in Davenport and a town meeting in Burlington, Iowa, not a single person asked about Young, the Mideast of the Palestine Liberation Organization (PLO). "People out in the country are not nearly as excited as the press about personnel changes or little transient squabbles" in Washington, the president said in Burlington.

Looking at differently, that dismissal was a convenient way to avoid the realities of the issue and the no-win dilemma it poses for Carter.

"These are very difficult times.Great sensitivities are involved. I don't consider this a black-versus-Jew issue," said a White House official. "But if the president were to do anything, the question is, would he make the situation better or worse. . .it might only exacerbate the problem."

This mid-level official said the initial thought in the White House was that the controversy would flare for a few days, then disappear.

But then came the black leaders, meeting in New York Wednesday. It was said to be the largest gathering of black leaders in more than a decade, and the emotions and racial-ethnic overtones generated by Young resignation were high.

"Now that it's reached another stage, we have to think of alternatives," the White House official said. "What's happening now is not in the best interest of the country."

Carter could, the official said, try to bring black and Jewish leaders together, or he could just say something in response to questions. As yet, no real alternatives have been discussed, he said. And White House strategists haven't even met on the issue.

"I think there's a feeling that it's sort of played itself out," said an assistant to Vice President Mondale. "It's not just a question of should the president say something. I don't know what he could say that would help."

So the president's men are moving very slowly, and with good political reason. The White House fears that anything Carter says about Young's resignation under fire runs the risk of further angering blacks, who helped Carter win election in the first place.

Controversy also didn't fit into the White House's idea of steamboat politics. Steamboat politics were pure and simple image politics. The public wasn't supposed to see an increasingly unpopular president fending off attacks from aboard a steamboat.

Instead, they were supposed to receive images of the president standing beside a colorful old paddlewheeler, images of a president jogging, images of a president kissing babies, and surrounded by huge crowds everywhere he went. And they did. The tactic worked to well that at one point press secretary Jody Powell joked to reporters that he's written up a three-paragraph defense of Carter's policy on baby kissing. Carter never used any such statement.

Powell, the only senior policy adviser on the trip, repeatedly refused to answer basic questions about the Young affair and he tried to minimize the importance of other foreign policy questions.

At one point he said a controversy within the administration over Mideast policy "doesn't amount to a hill of beans." At another, he barked at NBC television correspondent Judy Woodruff, who had asked him a rather low-key foreign policy question: "Judy, I know you can't find any place to get your hair done along the river, but you don't have to take it out on me."

At the White House, a number of top-level aides were also on vacation. But a number of those remaining felt very uncomfortable with the picture of Carter floating down the Mississippi and playing the calliope while the black-vs.-Jew issue festered.

Some said they have come to think that Carter is simply unlucky. "It sometimes seems every time he does something good he gets another unlucky break," said one.

Last week, Mondale did make a series of calls to black and Jewish leaders in an effort, as a White House official put it, to become "an area of treelessness between two forest fires." But by Friday he was off on a trip to China.

One of those he talked to was Hyman Bookbinder; Washington representative of the American Jewish Committee. He said he told Mondale that Carter should not have accepted Young's resignation. "The president should have realized that by letteng him go over this Palestinian issue it would raise other issues. . .namely tensions between blacks and Jews," Bookbinder said.

"Young was at least using some imagination in trying, in good faith, to entice the PLO into negotiations."

Bookbinder added that he was "pained" by the statement of the 200 black leaders in New York Wednesday. "I'm concerned that things don't get out of hand," he said. "There's a lot of anger now. I just hope my fellow Jews don't react in kind."

Meanwhile, Carter was keeping his own counsel as tensions between blacks and Jews increased in the big cities in the East, far from the Mississippi. He would be asked about the Young Affair and its aftermath, but he chose, for the moment, a nonloquacious task.

He must know somethin'! But he don't say nothin'; 'he just keeps

He must know somethin'. But he don't say nothin'; 'he just keeps rollin', he keeps rollin' along. rollin', he keeps rollin' along.