In the half-lit world of political financing, James P. Wilmot long has been a mainstay of the Democratic Party. Former House Speaker Carl Albert says he was "a real good man to know when you have one-third as much money as the Republicans have."

But the financial empire of the 63-year-old self-made millionaire is under legal seige, and his political fortunes appear to be on the wane.

Beset by private suits and federal investigations into his financial dealings, Wilmot now has become something of an embarrassment to the very Democrats who not so long ago courted his favor.

In an era of campaign reform and greater scrutiny of corporate activities at home and abroad, Wilmot's tough-hewn approach to business and politics seems peculiarly out of step with the times.

His companies' aggressive policy of acquisition and expansion has resulted in a variety of charges that he violated federal antitrust and securities laws. These include:

A 1977 federal court decision ordering Page Airways, A Wilmot-run firm that sells and services private aircraft, to pay$9 million in damages for antitrust violations. Page, a $72-million-a-year company, is appealing the decision.

A 1978 Securities and Exchange Commission suit charging that Page and six of its executives made $2.5 million in undocumented payments to foreign governments, among them Idi Amin's Uganda. The suit has not come to trial.

An ongoing Department of Transportation audit of Page's $10-million-a-year contracts to service and fuel all private aircraft at Washington National and Dulles International airports. An earlier Federal Aviation Administration audit showed the Page contracts had been extended five times without public bidding and that Page had understated its government fees by as much as $2 million. Page is challenging the FAA audit.

An ongoing Department of Transportation audit of Page's $10-million-a-year contracts to service and fuel all private aircraft at Washington National and Dulles International airports. An earlier Federal Aviation Administration audit showed the Page contracts had been extended five times without public bidding and that Page had understated its government fees by as much as $2 million. Page is challenging the FAA audit.

An ongoing federal grand jury investigation in upstate New York into a Wilmot-run construction firm that stands to receive $88 million in federal rent subsidies from the Department of Housing and Urban Development. That same firm built Uganda's lavish mission to the United Nations and supervised work on National Airport's General Aviation Terminal.

Stock analysts familiar with Page say the company hasn't paid dividends for two years. Stock analysts speculate the company is readying itself to pay out the $9 million antitrust judgment if it isn't overturned on appeal. Analysts also speculate Page is trying to build up reserves to meet legal expenses.

Until the recent spate of litigation and investigations, Wilmot was best known as a major behind-the-scenes contributor with direct or indirect access to the nation's most powerful figures.

A Wilmot spokesman said Wilmot never has asked a favor of anyone to whom he has made a political contribution. But an episode involving House Speaker Thomas P. O'Neill illustrates the political contacts Wilmot enjoyed.

In December 1975, Wilmot several members of his family and some business associates contributed $10,000 to the Thomas P. O'Neill Jr. Congress Fund. A few months later, O'Neill telephoned Carla Hills, then HUD secretary, to "inquire" about some $2.2 million in federal rent subsidies due a Wilmot construction project in upstate New York. HUD officials say the funds were being held up pending the release of an environmental impact study on the project. Shortly after O'Neill's call, the federal funds were released.

This wasn't the first time that a speaker of the House went to Wilmot's aid. Former House speaker Carl Albert also apparently made phone calls on Wilmot's behalf.

According to a 1974 memo of a trade association representing the charter-flight industry, John Jarman, then a U.S. representative, telephoned the association to voice Carl Albert's concern over the group's challenge to Page's fueling monopoly at Dulles. Albert had received a complaint from Geral "Tiny " Wilmot, James Wilmot's brother and himself a Page executive, according to the memo. Only after the DOT intervened on the group's behalf were its members permitted to buy fuel from companies other than Page.

Jarman couldn't be reached for comment. Albert said he doesn't recall making that particular call but that he may have. "If he asked me to check the status of anything that I didn't think was crooked, I would have done it for him (Wilmot)," Albert said in a recent interview.

Albert acknowledged that he and other congressmen had been guests of Wilmot and had been flown to his Rochester estate At Wilmot's expense.

Wilmot's house guests included the late Hubert Humphrey, a close personal friend of Wilmot's and a direct beneficiary of Wilmot's fund-raising skills. While vice president, Humphrey occasionally hunted pheasant on Wilmot's private game preserve in Rochester, N.Y.

In recent years, Wilmot and various members of his family and executives from his firms have made campaign contributions of $21,000 to Senate Aviation Subcommittee member Daniel K. Inouye, $11,000 to Sen. Howard Cannon, chairman of that committee and $30,000 to New York Gov. Hugh Carey. Sens. Henry Jackson and Sam Nunn, and Reps. Thomase E. Foley, John J. McFall, Jim Wright and others have received contributions of $1,000 or more from Wilmot and his associates.

"Every worthy Democrat who has run for office" in New York has won Wilmot's support, said a spokesman for Carey.

"He has tremendous clout. The Democratic Party will be in hock to him for years," said Eli Freedman, Rochester's former city manager.

Although federal campaign laws limit individual contributions to $1,000, Wilmot and his family and associates have given far in excess of that amount in aggregate contributions.

But Wilmot's political influence appears to be waning as the new breed of Democratic leaders shies away form this contributor's notoriety.

Sen. Daniel P. Moynihan, an outspoken critic of Idi Amin, cancelled an April 1978 fund-raiser at Wilmot's Rochester home after press reports disclosed that Wilmot had give Amin a Cadillac Eldorado convertible.

Wilmot and the senator agreed it would be disadvantageous to both men to go ahead with the affair, according to Tim Russert, a Moynihan aide.

From the beginning, Wilmot had a knack for politics and a business sense that helped carry him from poverty to vast personal wealth and influence. "He literally crawled up in this world by his fingernails," said one business associate who asked not to be named. "He's a guy of tremendous wealth and power, and he knows how to use both. He is not a guy to be messed with lightly."

Born in Boston to a family of Irish immigrants and the eldest of six children, Wilmot was on his own at an early age. His father died when he was 10. When he was 19, the family tailor shop closed and he was forced to help support the family.

At 21, he mixed in Rochester's Democratic wards, organizing the poor and unemployed. He became a formidable Democratic force locally, according to associates. During his career, Wilmot has held a number of government jobs, including a job with the Federal Works Progress Administration and a position with the city as recreation director. Later he was appointed assistant manager of Rochester's airport.

In 1939, he joined a young pilot named Elmer Page and started Page Airways, giving flying lessons with one leased Piper Cub. But it was a federal contract to train pilots for the Civilian Pilot Training Program and later the Army that kept the fledgling Page Airways in business in those early days of 1940, according to Page.

Today federal contracts account for an estimated $100 million of Wilmot's financial empire. The contracts include payments from the Air Force, the Army Corps of Engineers and the General Services Administration, and Defense Department contracts to federally subsidized housing.

The firm also enjoyed the lucrative exclusive right to sell Grumman executive jets worldwide for a number of years. That arrangement collapsed in 1976, costing Page an enormous portion of its yearly revenues. Page sued Gulfstream American Corp.(formerly Grumman American Aviation Corp.) in December 1978, and Grumman brought a counterclaim. The suit hasn't gone to trial.

Also contributing to this story was Washington Post staff researcher Regina Fraind.