WASHINGTON -- Antonin Scalia, the influential conservative and most provocative member of the Supreme Court, has died, leaving the high court without its conservative majority and setting up an ideological confrontation over his successor in the maelstrom of a presidential election year. Scalia was 79.

Scalia was found dead Saturday morning at private residence in the Big Bend area of West Texas, after he'd gone to his room the night before and did not appear for breakfast, said Donna Sellers, speaking for the U.S. Marshals Service in Washington. The cause of death was not immediately known. A grey hearse was seen at the entrance to the Cibolo Creek Ranch, near Shafter, on Saturday accompanied by an SUV.

President Barack Obama made clear Saturday night he would nominate a successor to Scalia, despite calls from Republicans to leave that choice -- and the certain political struggle over it -- to the next president. He promised to do so "in due time" while paying tribute to Scalia as "one of the towering legal figures of our time."

Scalia's death most immediately means that that the justices could be split 4-4 in cases going to the heart of the some of the most divisive issues in the nation -- over abortion, affirmative action, immigration policy and more.

Scalia was part of a 5-4 conservative majority -- with one of the five, Anthony Kennedy, sometimes voting with liberals on the court. In a tie vote, the lower court opinion prevails.

Senate Majority Leader Mitch McConnell, as well as Republican presidential candidates Ted Cruz and Marco Rubio, said the nomination should fall to the next president.

Democrats were outraged at that idea, with Sen. Harry Reid, the chamber's top Democrat, saying it would be "unprecedented in recent history" for the court to have a vacancy for a year.

Scalia used his keen intellect and missionary zeal in an unyielding attempt to move the court farther to the right after his 1986 selection by President Ronald Reagan. He also advocated tirelessly in favour of originalism, the method of constitutional interpretation that looks to the meaning of words and concepts as they were understood by the Founding Fathers.

Scalia's impact on the court was muted by his seeming disregard for moderating his views to help build consensus, although he was held in deep affection by his ideological opposites Ruth Bader Ginsburg and Elena Kagan. Scalia and Ginsburg shared a love of opera. He persuaded Kagan to join him on hunting trips.

His 2008 opinion for the court in favour of gun rights drew heavily on the history of the Second Amendment and was his crowning moment on the bench.

He could be a strong supporter of privacy in cases involving police searches and defendants' rights. Indeed, Scalia often said he should be the "poster child" for the criminal defence bar.

But he also voted consistently to let states outlaw abortions, to allow a closer relationship between government and religion, to permit executions and to limit lawsuits.

He was in the court's majority in the 2000 Bush v. Gore decision, which effectively decided the presidential election for Republican George W. Bush. "Get over it," Scalia would famously say at speaking engagements in the ensuing years whenever the topic arose.

Bush later named one of Scalia's sons, Eugene, to an administration job, but the Senate refused to confirm him. Eugene Scalia served as the Labor Department solicitor temporarily in a recess appointment.

A smoker of cigarettes and pipes, Scalia enjoyed baseball, poker, hunting and the piano. He was an enthusiastic singer at court Christmas parties and other musical gatherings, and once appeared on stage with Ginsburg as a Washington Opera extra.

Ginsburg once said that Scalia was "an absolutely charming man, and he can make even the most sober judge laugh." She said that she urged her friend to tone down his dissenting opinions "because he'll be more effective if he is not so polemical. I'm not always successful."

Quick-witted and loquacious, Scalia was among the most persistent, frequent and quotable interrogators of the lawyers who appeared before the court.

During Scalia's first argument session as a court member, Justice Lewis F. Powell leaned over and asked a colleague, "Do you think he knows that the rest of us are here?"

Scalia was passionate about the death penalty. He wrote for the court when in 1989 it allowed states to use capital punishment for killers who were 16 or 17 when they committed their crimes.

The only child of an Italian immigrant father who was a professor of Romance languages and a mother who taught elementary school, Scalia graduated first in his class at Georgetown University and won high honours at the Harvard University Law School.

He worked at a large Cleveland law firm for six years before joining the faculty of the University of Virginia's law school. He left that job to work in the administrations of Presidents Richard Nixon and Gerald Ford.

From 1977 to 1982, Scalia taught law at the University of Chicago.

He then was appointed by Reagan to the U.S. Circuit Court of Appeals for the District of Columbia. Scalia and his wife, Maureen, had nine children.