By Doina Chiacu
WASHINGTON (Reuters) - Republican lawmakers and presidential candidates hardened their positions on Sunday on blocking a move by President Barack Obama to replace the late conservative Justice Antonin Scalia on the Supreme Court, a lifetime appointment that would help decide some of the most divisive issues facing Americans.
The next justice would tilt the balance of the nation's highest court, which now consists of four conservatives and four liberals. The vacancy left by the death of Scalia, 79, quickly became an issue in the 2016 presidential race.
"We ought to make the 2016 election a referendum on the Supreme Court," U.S. Senator and Republican presidential candidate Ted Cruz said on NBC's "Meet the Press."
The nine-justice court is set to decide its first major abortion case in nearly 10 years, as well as cases on voting rights, affirmative action and immigration.
Cruz said the vacancy makes November's election even more critical, warning that a justice chosen by Democratic candidates Hillary Clinton or Bernie Sanders would mean the Second Amendment right to bear arms would be "written out" of the Constitution and abortion on demand would become the law of the land.
He lumped Donald Trump in with the Democrats, saying that the Republican front-runner's views were indistinguishable from theirs.
Democrat Obama said on Saturday that he would nominate someone to fill the now-empty seat, setting up a battle with the Republican-controlled Senate, which must approve any nominee.
Senate Republican leader Mitch McConnell said hours after Scalia's death was announced that the high court vacancy should not be filled until Obama's successor takes office next January so that voters can have a say in the selection.
His Democratic counterpart, Harry Reid, said failure by the Senate to act would be a "shameful abdication" of the chamber's constitutional responsibilities.
While Reid said it would be unprecedented to have a vacancy on the highest court for a year, Republicans said no appointment should be made in the so-called lame-duck year of a presidency.
"The president can decide whatever he wants, but I'm just telling you the Senate is not moving forward on it until we have a new president, and I agree with that," Senator Marco Rubio, a Republican presidential candidate, said on CBS's "Face the Nation."
Asked what litmus test he would apply to any nominee, Rubio's criteria echoed Scalia's "originalist" ideology that looks at the U.S. Constitution through the lens of its framers' 18th century intentions.
"Does the person that we are nominating have a consistent and proven record of interpreting the Constitution as initially meant? What do those words mean to that society at the time in which those words were written in the Constitution? That's what I want out of a judge, out of a justice," Rubio said.
Trump, appearing on NBC, was more direct when asked what he would want in a nominee: "Someone just like Justice Scalia."