Washington ? The Senate’s No. 2 Republican on Sunday refused to rule out a filibuster if President Barack Obama seeks a Supreme Court justice who decides cases based on “emotions or feelings or preconceived ideas.”

Sen. Jon Kyl made clear he would use the procedural delay if Obama follows through on his pledge to nominate someone who takes into account human suffering and employs empathy from the bench. The Arizona Republican acknowledged that his party likely does not have enough votes to sustain a filibuster, but he said nonetheless he would try to delay or derail the nomination if Obama ventures outside what Kyl called the mainstream.

“We will distinguish between a liberal judge on one side and one who doesn’t decide cases on the merits but, rather, on the basis of his or her preconceived ideas,” Kyl said.

The White House is preparing to announce Obama’s pick to replace Justice David Souter, who plans to retire back to his beloved New Hampshire when the court’s term ends. Sen. Dick Durbin of Illinois, the No. 2 Democrat in the Senate, said Sunday that he has been told a choice is likely to be announced this week. Those involved with Obama’s decision hint that it could come as early as Tuesday.

Obama, who has interviewed at least two candidates for the position, has offered hints into what he wants in a justice.

“You have to have not only the intellect to be able to effectively apply the law to cases before you,” Obama said in an interview carried Saturday on C-SPAN television. “But you have to be able to stand in somebody else’s shoes and see through their eyes and get a sense of how the law might work or not work in practical day-to-day living.”

Obama also has said he wants someone who employs empathy, “understanding and identifying with people’s hopes and struggles,” when arriving at decisions that could influence the nation for decades.

That approach drew a rebuke Sunday from Kyl, who in January told the conservative Federalist Society that he reserved the right to filibuster.

“I went on to say a lot of things about what I meant by that, and I was distinguishing between a person who is just liberal — and undoubtedly this nominee will be liberal — and one who decides cases not based upon the law or the merits but, rather, upon his or her emotions, or feelings or preconceived ideas. That would be a circumstance in which I could not support the nominee,” Kyl said.