WASHINGTON >> A spotlight quickly focused on two Republican senators Thursday in the fight-to-come over President Donald Trump’s Supreme Court nomination — Susan Collins and Lisa Murkowski, whose support for abortion access will reverberate throughout the debate.

Every vote matters in the narrowly divided chamber, and the two women are already facing enormous pressure. Activist groups, particularly those aligned with Democrats, want them to rule out voting for a conservative nominee who might make precedent-shattering court decisions on abortion, gay marriage and other social issues.

Murkowski, of Alaska, made no such promise. But she vowed a careful vetting of the person President Donald Trump picks, saying she has “extremely high” standards for the court and the person who will replace retiring Justice Anthony Kennedy.

“There is no doubt that the president’s nominee to succeed Justice Kennedy can expect exacting scrutiny from the Senate and that is the standard I will apply in evaluating the nominee,” she said.

Collins, meanwhile, declared that the landmark Roe v. Wade decision that codified abortion rights is “settled law.”

“I always look for judges who respect precedent,” the Maine senator said to reporters.

Trump is expected to announce his nominee within a few weeks. In the meantime, advocacy groups are wasting no time jumping into the emerging campaign for Kennedy’s replacement, who could tip the court’s balance toward conservatives for years to come.

In general, conservatives are pushing for speedy confirmation before the November congressional elections. But some in the GOP are looking to the political impact of a prolonged confirmation battle to drive up voter turnout.

Trump said Kennedy’s decision to retire at this point “showed confidence in us” to make a good choice for his successor.

Democrats argue that the confirmation action should be put on hold until after the elections. They are citing Republican leader Mitch McConnell’s successful block of President Barack Obama’s nominee to the court, Merrick Garland, in 2016.

McConnell says the situations are not the same.

“This is not 2016. There aren’t the final months of a second-term constitutionally lame duck presidency with a presidential election fast approaching. We’re right in the middle of this president’s very first term,” McConnell said.

Whatever the timing, the confirmation fight is likely to consume the Senate through fall and become a defining issue for the midterm election battleground.

Sen. John Cornyn of Texas, the second-ranking Republican, noted the pressure.

“On the outside there’s going to be World War III,” he said.

Cornyn, who is the Senate GOP’s chief vote counter, said he was confident in holding the Republican majority, including Collins and Murkowski, behind Trump’s eventual nominee. He suggested several Democratic senators would cross over for bipartisan support.

“Every senator’s got to make up their own mind,” he said.

Republican colleagues of Collins and Murkowski did not doubt their resolve to vote as they see fit.

“Listen, Lisa Murkowski and Susan Collins can handle pressure,” said Marco Rubio of Florida. “They’re going to do what they believe is right. They’re not going to respond to pressure from either side.”

Republicans hold a narrow 51-49 majority in the Senate, and it’s even close because of the absence of ailing Sen. John McCain of Arizona. Even though Republican leader McConnell changed Senate rules last year to allow confirmation by simple majority, if Democrats hold together he cannot afford defections. Vice President Mike Pence can be called on to break a tie.

Last year, Trump’s first nominee to the court, Neil Gorsuch, was confirmed 54-45, with three Democrats voting in favor.

Those Democrats — Joe Manchin of West Virginia, Joe Donnelly of Indiana and Heidi Heitkamp of North Dakota— all are facing difficult re-election races and could find it difficult to oppose the president’s second pick.

Manchin indicated Thursday he was keeping an open mind.

“I just think you have to go through a process,” he said. “I want qualifications. Somebody that’s well qualified, understands the Constitution and the rule of law.”

Trump’s legislative director Marc Short said the White House has begun conversations with several Senate offices. Donnelly would not say whether that has included him.

Tony Perkins, president of the Family Research Council, a leading evangelical and conservative advocate, was among those suggesting it might make sense to put off a vote on the nominee. He said a vacancy on the court in 2016 helped boost enthusiasm among evangelicals for Trump.

“Part of me says I would like to see it after the election because I think it will just fuel the turnout and have more participation in the election,” Perkins said.

Several Democratic senators considering 2020 presidential runs jumped into the debate Thursday, rallying from the steps of the Supreme Court. Sen. Cory Booker pledged a long-term battle to prevent Trump from rushing a conservative judge onto the court.

“We now must fight,” the New Jersey Democrat said.

Sen. Kirsten Gillibrand said Kennedy’s retirement sets up a situation where “women’s lives are at risk.”

In announcing Kennedy’s retirement this week, Trump said he would start the effort to replace him “immediately” and would pick from a list of 25 names that he updated last year.

McConnell declared that the Senate “will vote to confirm Justice Kennedy’s successor this fall.” But that left the timing open for debate.

Possible nominees being eyed include Thomas Hardiman, who has served with Trump’s sister, now on senior inactive status, on the 3rd U.S. Circuit Court of Appeals in Philadelphia, and Raymond Kethledge, a federal appeals court judge who clerked for Kennedy. Also of interest are Amul Thapar, a federal appeals court judge from Kentucky who is close to McConnell; Brett Kavanaugh, a former clerk for Kennedy who serves on the federal appeals court in Washington, D.C., and Amy Coney Barrett, who serves on the federal appeals court in Chicago.