Republican presidential candidate Sen. Ted Cruz (R-TX) participates in the South Carolina Faith and Family Presidential Forum Friday in Greenville, S.C. (Alex Wong/Getty Images)

The U.S. Supreme Court — and the array of contentious social issues that it decides — has become a major focus of the 2016 elections and is almost certain to remain that way for the rest of the year.

The unexpected death Saturday of Justice Antonin Scalia, regarded as the dominant figure of the court’s conservative majority, has left it deeply divided, much as the country is.

And the question of who might replace Scalia will draw into even sharper relief the nation’s political and ideological fault lines.

“It reminds us of this — how important this election is,” Sen. Marco Rubio (R-Fla.) said Saturday night at the GOP presidential debate, which was sponsored by CBS News.

With a year left in President Obama’s term, it is likely that it will be left to his successor to appoint a replacement, who would determine whether the court leans left or right.

Antonin Scalia died on Saturday, Feb. 13. Here's a look back on his tenure, his judicial philosophy and the legacy he leaves behind. (Monica Akhtar,Natalie Jennings/The Washington Post)

Shortly after the announcement of Scalia’s death, Senate Majority Leader Mitch McConnell (R-Ky.) issued a statement saying that the Senate should not confirm a replacement until after the presidential election. Obama plans to send a nominee to the Senate, but it is unlikely that any could get through, especially given that two senators are among those vying for the GOP nomination.

“The American people should have a voice in the selection of their next Supreme Court justice,” McConnell said.

That elevates the makeup of the court to a front-line issue in the presidential race. It also appears certain to become a central focus in Senate races across the country, as that chamber has the power to confirm whomever the next chief executive would choose.

“Before today, it was unlikely that many voters would choose a presidential candidate for this reason, given the importance of issues like the economy, terrorism, and immigration,” wrote Tom Goldstein, publisher of SCOTUSblog. “But the fact that there is an immediate vacancy — and a vacancy that could tip the Court’s ideological balance — makes the future of the Court much more concrete.”

The candidates are certain to be pressed — constantly — to describe the qualifications they will look for in a nominee, as well as the litmus-test questions that would determine their choices.

“The simple fact is the next president has to appoint someone with a proven conservative record,” former Florida governor Jeb Bush said during Saturday night’s GOP debate.

Republicans will pledge to appoint strict constructionists who will follow the letter of the Constitution, and they will also be under pressure to pledge that their choices would roll back court decisions that upheld the Affordable Care Act and legalized same-sex marriage.

Democrats will press for nominees who would overturn court decisions such as the one that opened the floodgates for unregulated money in elections and who would hold the line against efforts to narrow voting rights protections and access to abortion.

Even with a conservative majority, the court has been a target on the right. Shortly after it ruled last July in favor of same-sex marriage, Sen. Ted Cruz of Texas, now a GOP presidential contender, proposed a constitutional amendment that would impose term limits on Supreme Court justices.

“This past term, the court crossed a line and continued its long descent into lawlessness to a level that I believe demands action,” Cruz said.

In an era when the legislative and executive branches have been at loggerheads, it has increasingly fallen to the court to decide the direction of major political issues and even to weave the social fabric of the nation.

During Obama’s years in office, that has included decisions on the fate of the Affordable Care Act, same-sex marriage, environmental issues, immigration policy, voting rights and redistricting, religious freedom, racial discrimination, reproductive rights and the extent of presidential powers.

The court faces a number of controversial decisions this term as well — all of which will elevate the question of who will replace Scalia.

Obama has made two picks for the court, neither of whom shifted its ideological balance. Liberals Elena Kagan and Sonia Sotomayor were replacements for others who generally voted that way, David Souter and John Paul Stevens.

Usually, discussions of Supreme Court nominations during presidential elections are theoretical ones. Before Scalia’s death, the question of Supreme Court appointments had fallen into that category, given that four of the justices were in or approaching their 80s.

Democratic front-runner Hillary Clinton caused a recent stir when an Iowa voter asked if she might consider appointing Obama.

“Wow, what a great idea. Nobody has ever suggested that to me. Wow. I love that. Wow. He may have a few other things to do, but I tell you, that’s a great idea,” she replied.

“It is true the next president may get anywhere from one to three Supreme Court appointments,” Clinton added. “I think the Supreme Court has really unfortunately been headed in the wrong direction, and we need new justices who will actually understand the challenges we face. You know, I can’t tell whether it’s just naivete, or it’s just ideological, theoretical views.”

On the Republican side, leading candidate Donald Trump caused consternation in December, when he criticized Scalia for questioning affirmative action.

After Scalia said that minority students who did not qualify for elite universities might do better at “less advanced schools,” Trump said: “I don’t like what he said, no, I don’t like what he said. . . . I’m going, ‘Whoa.’ ”

On Saturday, Trump issued a statement saying that Scalia was “a remarkable person and a brilliant Supreme Court justice, one of the best of all time.”