CONSERVATIVE PARTY FOUNDER MAHONEY.

Byline: Lawrence Van Gelder The New York Times

Judge J. Daniel Mahoney of the 2nd Circuit U.S. Court of Appeals, a founder of the New York state Conservative Party, died Wednesday at Griffin Hospital in Derby, Conn. Mahoney, who lived in Huntington, Conn., was 65.

His family said the cause was a cerebral hemorrhage.

In a busy life, Mahoney practiced law with distinguished New York City law firms, represented well-known clients like writer William F. Buckley Jr. and ice skater Dorothy Hamill and took part in significant decisions after he was sworn in as a judge in 1986. But he achieved his greatest prominence as the chairman of the Conservative Party.

The story of how Mahoney anticipated and helped harness the conservative tide that was rising in the nation and in the state began over lunch in 1962, when he and a brother-in-law, Kieran O'Doherty, decided to found a new party because they thought that the Republican Party under Gov. Nelson Rockefeller was too liberal.

Less than a decade later - after steady growth from 2.4 percent of the gubernatorial vote in 1962 and 8.5 percent in 1966 and 17.3 percent in the senatorial race of 1968 - Conservative Party candidate James L. Buckley was elected U.S. senator from New York in 1970, with 2 million votes cast on the Conservative line.

Working with a nucleus of young Republican lawyers employed by Wall Street law firms, O'Doherty provided the party's drive and vigor, Mahoney its polish and diplomacy.

``The Conservative Party stands for what the Republican Party stands for naturally, at its better moments,'' Mahoney said in 1970. ``We're struggling toward an honest two-party system between liberals and conservatives on a national level.''

Philosophically, the party espoused a traditional conservative view of government: the less the better, except in national defense. Its first manifesto called for firm anti-communism and weak federal and state government and emphasized ``the private energies of individuals and nongovernmental associations.''

It advocated lower taxes, less governmental spending and the control of education by parents and local communities.

Later it took stands against Medicaid, civilian police review boards, fluoridation of water, increased state aid for education, school busing to achieve racial balance, rent control and abortion.

On the national scene, the party backed the presidential campaigns of Barry Goldwater, Richard M. Nixon and Ronald Reagan. In New York City, Mahoney led William F. Buckley's unsuccessful campaign for mayor in 1965 as well as James F. Buckley's successful senatorial run in 1970.

As its power grew, the Conservative Party, like the Liberal Party before it, achieved a balance of power in some elections. In 1980, Alfonse D'Amato's uphill fight for the Senate received its initial impetus from the Conservatives, and in 1994, the party's 328,000 votes played a pivotal role in the election of Gov. George Pataki. He defeated the incumbent, Mario Cuomo, by less than 200,000.

But when Reagan appointed Mahoney to the 2nd Circuit, which includes New York, Connecticut and Vermont, he said he would not bring any ideological baggage with him.

``I've been a pretty active lawyer, as well as politician,'' he said. ``It's not a question of ideology. It's understanding that a judge is supposed to be impartial and should not use the judiciary as a platform for proselytizing any personal views.''

Mahoney is survived by his wife of 41 years, the former Kathleen O'Doherty, and three sons and three daughters: J. Daniel Mahoney Jr. of Scottsdale, Ariz.; Kieran V. Mahoney of Manhattan; Francis K. Mahoney of Darien, Conn.; Mary Shipman of Queens; Eileen Curley of Pleasantville, N.Y., and Elizabeth Mahoney of Manhattan; and his brother, William D. Mahoney of Larchmont, N.Y.