ROBERT H. BORK, who stepped in to fire the Watergate prosecutor at Richard Nixon's behest and whose failed 1987 nomination to the Supreme Court helped draw the modern boundaries of cultural fights over abortion, civil rights and other issues, died Wednesday. He was 85.

Robert H. Bork Jr. confirmed that his father died at Virginia Hospital Center in Arlington, Va., from complications of heart ailments.

Brilliant, blunt and piercingly witty, Robert Heron Bork had a long career in the law that took him from respected academic to a totem of conservative grievance.

Along the way, Bork was accused of being a partisan hatchet man for Nixon when, as the third-ranking official at the Justice Department, he fired Watergate special prosecutor Archibald Cox in the Saturday Night Massacre of 1973.

Bork's drubbing during his Senate nomination hearings made him a hero to the right and a rallying cry for younger conservatives.

Supreme Court Justice Antonin Scalia called his former appeals-court colleague "one of the most influential legal scholars of the past 50 years. His impact on legal thinking in the fields of antitrust and constitutional law was profound and lasting."

Long mentioned as a possible Supreme Court nominee, Bork got his chance toward the end of Ronald Reagan's second term. He was nominated July 1, 1987, to fill the seat vacated by Justice Lewis F. Powell.

Nearly four months later, the Senate voted 58-42 to defeat him after the first national political and lobbying offensive mounted against a judicial nominee.

It was the largest negative vote ever recorded for a Supreme Court nominee.

Stoic and stubborn throughout, Bork refused to withdraw when his defeat seemed assured.

The fight has defined every high-profile judicial nomination since, and largely established the opposing roles of vocal and well-funded interest groups in Senate nomination fights. Bork would say later that the ferocity of the fight took him and the Reagan White House by surprise, and he rebuked the administration for not doing more to salvage his nomination.

The process begot a verb, "to bork," meaning vilification of a nominee on ideological grounds.