LA QUINTA, CALIFORNIA (AFP/REUTERS) - United States President Barack Obama extended condolences to the family of Supreme Court Justice Antonin Scalia on Saturday (Feb 13), as news of his death sent ripples through US politics.

And he vowed to nominate a replacement in a statement late on Saturday.

Mr Obama said on Saturday that he planned to fulfill his constitutional responsibility to nominate a Supreme Court justice to fill the vacancy.

He pressed the Republican-led Senate to give his nominee a "fair hearing and a timely vote". "I plan to fulfill my constitutional responsibilities to nominate a successor in due time," Mr Obama said in California. "There will be plenty of time for me to do so and for the Senate to fulfill its responsibility to give that person a fair hearing and a timely vote.

"These are responsibilities that I take seriously as should everyone. They're bigger than any one party. They are about our democracy."

He paid tribute to Justice Scalia's legacy on the bench in brief remarks to reporters, but did not give any indication about who he would nominate to replace him, saying the nomination would come in due time.

Mr Obama was informed about the unexpected passing of the conservative justice as he was golfing with friends in California.

Justice Scalia, 79, received last rites from a Catholic priest at the Texas ranch where he died, Ms Elizabeth O'Hara, a spokesman for the Diocese of El Paso, said on Saturday.

Reverend Mike Alcuino, who serves at a parish in Presidio County, Texas, administered last rites to the justice, Ms O'Hara said.

"The President and first lady extend their deepest condolences to Justice Scalia's family," said White House spokesman Eric Schultz.

Justice Scalia's death sets up a monumental political fight during an already heated presidential election campaign. Replacing Scalia with a Democrat-appointed justice could significantly alter the balance of the court. But Republicans who control the Senate - which must approve Obama's nominee - immediately drew battle lines.

Top Republicans went as far as demanding that Obama not name a replacement at all, saying that should be a job for the next president. The election will take place in November and a new president will be sworn in in January.

"The American people should have a voice in the selection of their next Supreme Court Justice," the Senate Republican majority leader Mitch McConnell said in a statement.

"Therefore, this vacancy should not be filled until we have a new president."

The constitution calls on the president to nominate and appoint Supreme Court justices with the advice and consent of the Senate. The Supreme Court has played a significant role in US politics in recent years. It played a decisive part in the 2000 election by stopping a Florida recount in the fiercely contested ballot that brought former president George W. Bush to power.

More recently, it paved the way for non-governmental groups to pour money into election campaigns.

During Mr Obama's administration, the court has been asked to rule on a series of executive orders, which were designed to bypass Congressional opposition. Just this week, the court froze the implementation of a major White House effort to cut carbon emissions, after a Republican legal challenge.

But with a replacement unlikely to be appointed before the current Supreme Court term ends in June, there is the possibility it will be split 4-4 on a string of rulings.

When the court is equally divided, the lower court ruling remains in place but no national precedent is set.

Justice Scalia's death will affect cases that have not yet been argued and those in which arguments were already held but no ruling has been issued. Court experts say that any preliminary votes

Justice Scalia took on cases already argued will no longer count. His death could deprive the court's conservative majority of some major wins, but does not guarantee wins for liberal causes.

In the short term, Justice Anthony Kennedy, a conservative who sometimes sides with the four liberals, will still be the key vote.

That could change the outcome of a major case argued in January that could affect the influence of public-sector unions. The issue is whether public employees who do not want to join a union can be required to pay "fair share" service fees, which are equivalent to members' dues, without violating First Amendment rights of free speech and association.

Based on the oral arguments, it appeared the conservative majority was ready to vote against the unions. Now, a 4-4 split is a likely outcome, which would hand a win to the unions as that would leave the lower court's ruling in their favor in place.

Similarly, the court in December considered an important affirmative action dispute over whether a University of Texas admissions programme that considers the race of some applicants to ensure campus diversity violates the constitutional guarantee of equality. It was unclear based on the oral argument how the court would vote. Justice Elena Kagan was already recused in that case, so Justice Scalia's death means there can no longer be a 4-4 split. The liberal wing could now win if Justice Kennedy joins them. That would lead to an unexpected victory for affirmative action advocates.

The court has not yet heard oral arguments in three major cases in which Justice Scalia was likely to be a key vote on the conservative wing of the court.

On March 2, the court will consider a tough new abortion law in Texas that women's health providers say infringes upon the constitutional right of women to have an abortion. The law requires clinics carrying out abortions to have costly hospital-grade facilities and requires physicians carrying out abortions to have admitting privileges at a hospital within 30 miles of where they are operating. It is the court's first abortion case since 2007. If the court was split 4-4, the law would be upheld.

In April, the court is due to weigh Mr Obama's bid to resurrect his plan to shield more than four million illegal immigrants from deportation, a unilateral executive action he took in 2014 to bypass the Republican-led Congress.

Justice Scalia's death does not necessarily boost the administration's chances. Mr Obama's executive action was blocked by the lower courts, meaning a 4-4 split would leave that ruling intact.