Gerald Herbert, Associated Press
FILE - In this Feb. 17, 2016, file photo, Vice President Joe Biden speaks after touring the Port of New Orleans to commemorate the seventh anniversary of the American Recovery and Reinvestment Act in New Orleans. Biden, in a radio interview airing Thursday, Feb. 18, that President Obama is looking to nominate a Supreme Court candidate who has enjoyed past Republican support, offering some of the first indications of the president’s criteria in replacing the late Justice Antonin Scalia.

WASHINGTON — President Barack Obama is looking to nominate a Supreme Court candidate who has enjoyed past Republican support, Vice President Joe Biden said, offering some of the first indications of the president's criteria in replacing the late Justice Antonin Scalia.

In a radio interview airing Thursday, Biden disagreed with Republicans who insist that Obama hand off the decision to the next president. Still, Biden acknowledged that the Senate has a say in confirming the president's pick.

"In order to get this done, the president is not going to be able to go out — nor would it be his instinct, anyway — to pick the most liberal jurist in the nation and put them on the court," the vice president told Minnesota Public Radio. "There are plenty of judges (who) are on high courts already who have had unanimous support of the Republicans."

Biden's remarks came amid growing signs that some Republicans were softening their stance about considering Obama's nominee, despite Senate Majority Leader Mitch McConnell's insistence that Obama shouldn't even nominate a candidate.

Sen. Lisa Murkowski of Alaska said that his nominee should get a hearing, and others have left the door open. Sen. Susan Collins of Maine told the Portland Press Herald that Obama's nominee would get her "full attention" and that senators "should carry out our constitutional duty."

Former Supreme Court Justice Sandra Day O'Connor became the latest voice arguing Scalia's seat should be filled expeditiously. O'Connor, a Ronald Reagan nominee who retired in 2006, told Fox 10 in Phoenix she disagreed with those calling to wait for the next president.

"I think we need somebody there now to do the job," she said, "and let's get on with it."

Yet others Republicans were holding firm. Sen. Pat Toomey of Pennsylvania said that, barring an unlikely Obama decision to nominate someone in Scalia's mold who wouldn't change the court's balance, it is clear Obama won't get a nominee confirmed this year.

"For that reason, it might be just as well not to have a hearing that would sort of — might mislead the American people into thinking that this is just about the qualifications of the candidate," Toomey said in an interview with The Associated Press. "Because it's bigger than that."

As lawmakers weighed in, the debate was also catching fire among advocacy groups on all sides of the ideological spectrum. The Judicial Crisis Network, a conservative group headed by a former clerk to Justice Clarence Thomas, said it was spending more than $1 million on TV and radio ads in Washington arguing that "next president chooses the next justice."

Although the White House hasn't publicly disclosed any candidates Obama is considering, he's expected to look closely at a number of circuit court judges — including some who meet the benchmark that Biden laid out. Sri Srinivasan, who sits on the U.S. Court of Appeals for the District of Columbia Circuit, was confirmed by a vote of 97-0 less than three years ago by the Senate, which also unanimously confirmed Jane Kelly in 2013 to the St. Louis-based Eighth Circuit.

Biden, who presided over Supreme Court confirmation hearings in the Senate, took issue with the notion that a Scalia replacement can't be confirmed during Obama's final year.

"To leave the seat vacant at this critical moment in American history is a little bit like saying, 'God forbid something happen to the president and the vice president; we're not going to fill the presidency for another year and a half,'" Biden said.

Associated Press writers Sam Hananel in Washington, Marc Levy in Allentown, Pennsylvania, Doug Glass in Minneapolis and Patrick Whittle in Portland, Maine, contributed to this report.