Washington (CNN) Justice Antonin Scalia's death immediately triggered a monumental election-year battle in Washington over whether President Barack Obama should choose a successor who could tilt the Supreme Court toward liberals.

Within two hours of Scalia's death being reported, presidential candidates along with Republican and Democratic leaders on Capitol Hill were feuding over whether Obama should appoint a replacement for the eloquent and outspoken Scalia or wait for the next administration to make a decision. The battle lines underscored the huge political stakes in the 2016 election, which could cement the ideological balance of the court for years to come.

Obama said Saturday he would nominate a successor "in due time," but Republican Senate Majority Leader Mitch McConnell insisted the next administration should make the appointment.

"The American people should have a voice in the selection of their next Supreme Court Justice," the Kentucky Republican said. "Therefore, this vacancy should not be filled until we have a new President."

But Senate Minority Leader Harry Reid issued a scathing statement, previewing the heated fight ahead.

"The President can and should send the Senate a nominee right away," Reid said. "With so many important issues pending before the Supreme Court, the Senate has a responsibility to fill vacancies as soon as possible. It would be unprecedented in recent history for the Supreme Court to go a year with a vacant seat. Failing to fill this vacancy would be a shameful abdication of one of the Senate's most essential Constitutional responsibilities."

News of Scalia's death broke hours before the latest Republican presidential debate and added another explosive element to a heated GOP primary campaign. Even before Saturday, the fate of the Supreme Court was already a key election issue, given the possibility that the next President could get the chance to nominate at least two or three Justices due to the age of those on the bench and the possible shift of the ideological balance of the court.

Photos: Justice Antonin Scalia's life in photos Photos: Justice Antonin Scalia's life in photos U.S. Supreme Court Justice Antonin Scalia, who was found dead on Saturday, February 13, was one of the most influential conservative justices in history. He was 79. Hide Caption 1 of 22 Photos: Justice Antonin Scalia's life in photos President Ronald Reagan announces the nomination of Scalia to the Supreme Court on June 17, 1986, as a result of Chief Justice Warren E. Burger's retirement. Hide Caption 2 of 22 Photos: Justice Antonin Scalia's life in photos Scalia works in his office in Washington on July 28, 1986. Scalia, who was appointed in 1986, was the longest-serving justice on the Supreme Court. Hide Caption 3 of 22 Photos: Justice Antonin Scalia's life in photos Scalia appears before the Senate Judiciary Committee during his confirmation hearings in Washington on August 6, 1986. Hide Caption 4 of 22 Photos: Justice Antonin Scalia's life in photos Scalia, seen in a 1986 photo, was the first justice of Italian-American heritage and passed through confirmation with a unanimous vote. Hide Caption 5 of 22 Photos: Justice Antonin Scalia's life in photos Retiring Chief Justice Warren Burger, right, administers the oath to Scalia, as Scalia's wife, Maureen, holds the Bible on September 26, 1986. Scalia was the 103rd person to sit on the court. Hide Caption 6 of 22 Photos: Justice Antonin Scalia's life in photos U.S. Supreme Court justices pay their respects in front of the casket of former Chief Justice Warren E. Burger during a prayer ceremony in the Great Hall at the Supreme Court Building in Washington on June 28, 1995. Hide Caption 7 of 22 Photos: Justice Antonin Scalia's life in photos Scalia speaks to a crowd gathered at the Religious Freedom Monument in Fredericksburg, Virginia, to celebrate Religious Freedom Day on January 12, 2003. Scalia complained that courts have gone overboard in keeping God out of government. Hide Caption 8 of 22 Photos: Justice Antonin Scalia's life in photos Scalia shakes hands with U.S. Marines Corps Maj. Gen. Robert C. Dickerson, commanding general, upon Scalia's arrival at Marine Corps Base Camp Lejeune, North Carolina, for an official visit on March 12, 2004. Hide Caption 9 of 22 Photos: Justice Antonin Scalia's life in photos Scalia speaks to Presbyterian Christian High School students in Hattiesburg, Mississippi, April 7, 2004. Hide Caption 10 of 22 Photos: Justice Antonin Scalia's life in photos The casket of Chief Justice William H. Rehnquist lies in the Great Hall of the U.S. Supreme Court as Scalia and Sandra Day O'Connor, left, walk past on September 6, 2005, in Washington. Hide Caption 11 of 22 Photos: Justice Antonin Scalia's life in photos Members of the U.S. Supreme Court, Justice Ruth Bader Ginsburg, Justice Stephen Breyer, Justice Clarence Thomas, Justice David Souter, Justice William Kennedy, Justice Antonin Scalia, Justice Sandra Day O'Connor and Justice John Paul Stevens file out of the U.S. Supreme Court Building to attend funeral services for Chief Justice William Rehnquist on September 7, 2005, in Washington. Hide Caption 12 of 22 Photos: Justice Antonin Scalia's life in photos Surrounded by security, Scalia walks in the annual Columbus Day Parade on October 10, 2005, in New York City. Hide Caption 13 of 22 Photos: Justice Antonin Scalia's life in photos Scalia calls on people during a question-and-answer period at the American Enterprise Institute on February 21, 2006, in Washington. Scalia delivered the keynote address about foreign law and the debate about how it is used in American Law during the seminar called "Outsourcing Of American Law." Hide Caption 14 of 22 Photos: Justice Antonin Scalia's life in photos Heather Myklegard, Scalia, Dirk Kempthorne and U.S. President George W. Bush walk through the Rose Garden before Kempthorne is sworn in as the new interior secretary at White House on June 7, 2006, in Washington. Hide Caption 15 of 22 Photos: Justice Antonin Scalia's life in photos Scalia listens as U.S. President George W. Bush speaks at the the Federalist Society's 25th Anniversary Gala Dinner at Union Station in Washington, on November 15, 2007. Hide Caption 16 of 22 Photos: Justice Antonin Scalia's life in photos Scalia speaks during the American Bar Association's 59th annual antitrust law spring meeting in Washington on March 31, 2011. Hide Caption 17 of 22 Photos: Justice Antonin Scalia's life in photos Scalia testifies during a hearing before the Senate Judiciary Committee on October 5, 2011. The justice testified on "Considering the Role of Judges Under the Constitution of the United States." Hide Caption 18 of 22 Photos: Justice Antonin Scalia's life in photos Scalia and his wife, Maureen, arrive for a state dinner in honor of British Prime Minister David Cameron at the White House on March 14, 2012, in Washington. Hide Caption 19 of 22 Photos: Justice Antonin Scalia's life in photos Scalia conducts a naturalization ceremony for 16 new U.S. citizens during the commemoration of the 150th anniversary of President Abraham Lincoln's historic Gettysburg Address on November 19, 2013, at Gettysburg National Military Park in Gettysburg, Pennsylvania. Hide Caption 20 of 22 Photos: Justice Antonin Scalia's life in photos U.S. President Barack Obama greets Supreme Court Justices Clarence Thomas, Antonin Scalia, Sonia Sotomayor, Anthony Kennedy and John Roberts at Obama's inauguration for his second term of office. Hide Caption 21 of 22 Photos: Justice Antonin Scalia's life in photos Scalia speaks at the University of Minnesota as part of the law school's Stein Lecture series on October 20, 2015, in Minneapolis. Hide Caption 22 of 22

After observing a moment of silence to honor Scalia, the GOP candidates, who clashed in South Carolina, seized on his death to draw battle lines in the debate over his successor.

"I do not believe the President should appoint someone," Florida Sen. Marco Rubio said, warning that Obama would "ram down our throat a liberal justice."

Texas Sen. Ted Cruz, a former Supreme Court clerk, warned: "We are one justice away from a Supreme Court that would undermine the religious liberty of millions of Americans."

"The Senate needs to stand strong and say, 'We're not going to give up the U.S. Supreme Court for a generation by allowing Barack Obama to make one more liberal appointee,'" Cruz said.

Republican front-runner Donald Trump said he was sure that Obama would not listen to Republicans and would go ahead and name a nominee, adding "I think it's up to Mitch McConnell, and everybody else to stop it. It's called delay, delay, delay."

On the Democratic side, Hillary Clinton lined up with the Democratic leaders in Congress to seize on a issue that will now be at the center of her campaign.

"Barack Obama is President of the United States until January 20, 2017. That is a fact, my friends, whether the Republicans like it or not. Elections have consequences. The President has a responsibility to nominate a new justice and the Senate has a responsibility to vote," Clinton said during a visit in Denver.

Clinton's Democratic rival, Vermont Sen. Bernie Sanders, also issued a statement that offered sympathy while acknowledging philosophical differences. He did not however weigh in on the issue of the timing of a nomination.

"While I differed with Justice Scalia's views and jurisprudence, he was a brilliant, colorful and outspoken member of the Supreme Court. My thoughts and prayers are with his family and his colleagues on the court who mourn his passing."

Scalia, who was found dead Saturday, was one of the most influential conservative justices in history and forged a decades-long legacy that prolonged Ronald Reagan's conservative revolution, long after the President who nominated him left office. Scalia was also seen as a hugely powerful foe by liberal groups owing to his positions on issues like abortion and the Second Amendment, and those groups will pile enormous pressure on Obama to send a liberal justice to the court before he leaves office.

'One of the great battles'

CNN Senior Legal Analyst Jeffrey Toobin predicted "one of the great battles in United States history" looms over whether "Obama's nominee even gets a vote."

JUST WATCHED GOP candidates react to the passing of Justice Scalia Replay More Videos ... MUST WATCH GOP candidates react to the passing of Justice Scalia 02:32

"The Senate Republicans recognize how important it is to maintain a conservative majority on the court," Toobin said, noting that Obama would leave office in January. "The question will be whether President Obama's nominee, who I expect will come quickly, will get a vote at all in the remaining months of this presidency."

Scalia's death means that the 2016 election could effectively evolve into a battle involving all three branches of the U.S. government, the White House, the Supreme Court and Congress — given that there is a real chance the GOP could lose control of the Senate.

It also comes at a time when the Court is expected to decide several cases with huge political implications, including on abortion and affirmative action.

The new political showdown over the Supreme Court will ensure that Obama remains at the center of both the political stew in Washington and the battle to replace him at the point in his tenure when many presidents come to be regarded as lame ducks.