Judge Sonia Sotomayor's confirmation hearings begin tomorrow in Washington, D.C.

Among the issues Sotomayor is expected to be asked about -- the firefighter discrimination case she ruled on and her comment about the judgment of a "wise Latina" compared to that of a white man.

Speaking on "Face the Nation," Senator Jeff Sessions, the senior Republican who will question Sotomayor during the hearings, says her philosophy is incompatible with the American system.

He says Sotomayor must demonstrate she will not show bias in her rulings.

The chairman of the judiciary committee, Senator Patrick Leahy, says critics are nitpicking.

"I think she's going to have to answer to that because this is a mature judicial philosophy that she's stated," said Sessions. "She has criticized the idea that a woman and a man would reach the same results. She expects them to reach different results."

"I've asked her about her speeches and she says ultimately and completely the law controls. And as a judge she's shown over and over again ultimately and completely the law controls," said Leahy. "We've had a lot of judicial nominees, Republicans and Democrats, talk about their background and how that's influenced them."

The questioning section of Sotomayor's hearing is expected to begin Tuesday.