"Usually you think of a horse trader in that job," said former budget director David A. Stockman, who was live-in baby-sitter for Moynihan's children while he was a graduate student at Harvard. "He could be a wild card."
In an institution not always known for great intellects, Moynihan, a three- term Democratic senator from New York, is definitely one. He also stands out for his daring views and his towering ego.
In the 1960s, he warned about the breakup of black families and blamed welfare as a cause. In the 1970s, he set a new standard for undiplomatic bluntness at the United Nations. In the 1980s, he proposed cutting Social Security taxes, an idea repugnant to his fellow Democrats. And in 1990, he said Kuwait's government was not worthy of having U.S. troops sent in to save the emirate from Iraq's occupation.
Clearly, he is unlike the pragmatic, more politically disciplined horse traders who preceded him - Harry Byrd (D., Va.); Russell Long (D., La.); Bob Dole (R., Kan.); Bob Packwood (R., Ore.) and Bentsen.
"I think you can definitely count on some surprises," said Stephen Hess, a presidential scholar in Washington, who worked for Moynihan in 1969.
"One morning, he'll be reading some English philosopher and say, 'My God! Look how it was done in 1593,' and some staffer will be researching a new way to reform welfare," Hess added. "You shouldn't have too many intellectuals in the Senate, but a couple make it yeasty."
Although he speaks with an academic lilt, Moynihan comes from humble roots. He was born in Tulsa, Okla., and raised in the New York slum known as Hell's Kitchen. His father was an alcoholic who deserted the family when Moynihan was 10, and his mother moved the family from apartment to apartment.
Moynihan served in the Navy during World War II, received his bachelor's, master's and doctoral degrees from Tufts University in Medford, Mass., and won a Fulbright fellowship to the London School of Economics.
He worked for New York Gov. Averell Harriman in the 1950s, was an assistant labor secretary in the Kennedy and Johnson administrations and served as President Nixon's urban affairs adviser. He was President Gerald R. Ford's ambassador to India and the United Nations.
Moynihan, who declined to be interviewed for this article, has already signaled he will be quick to criticize Clinton when he feels the urge.
A week before the inauguration, Moynihan got testy over signs that Clinton was backing away from promises to overhaul the welfare system and cut the deficit in half within four years. The senator said he was hearing "the clatter of campaign pledges being tossed out the window."
He went on to complain in a Time magazine interview last week that he had not received "a single call" from Clinton since November. He also criticized some of the tax-increase proposals Clinton is thinking of sending Congress.
Clinton got the message. He called Moynihan, and aides declared that the two were on good terms and would work closely together. "We don't expect Moynihan to buy everything we sell, but we expect him to be very supportive of the President," said a senior White House official who handles Clinton's relations with Congress.
Still, Clinton's initial lack of deference to the chairman could prove
troublesome, say those who know Moynihan.
"I'm stunned that Clinton failed to call. It was an amazing oversight," said a former Moynihan aide, who did not want his name used. "Moynihan is a force to be reckoned with, and his willingness to be a team player rises dramatically with the contact he has with the President."
While colleagues and former aides speak glowingly of Moynihan's mind, they say it has also spawned a difficult personality. He is a quick-tempered, demanding boss, they say, who can irk other senators with his arrogance.
Despite his quirks, Moynihan has shown that, when he chooses, he can be a loyal Democrat.
Jack DeVore, Bentsen's spokesman, said the former finance chairman "felt Pat Moynihan was as good a team player as he had on the committee. Sen. Moynihan sometimes had to close his eyes and grit his teeth to support the chairman."
He has also shown that despite his eccentricities he knows how to play the game to the benefit of his New York constituents.
In 1991, as chairman of a Public Works subcommittee, Moynihan helped negotiate final details of a $151 billion transportation act, a huge piece of pork-barrel legislation that distributed funds to every congressional district for improving highways, mass transit, airports and waterways. New York was one of the biggest beneficiaries.