“Just a day or so ago, we discovered that there are 300 or so boxes of additional material that has just been discovered from her time working with the Puerto Rican Legal Defense Fund,” McConnell said in an interview on “Fox News Sunday.”

“The committee needs to have access to that material and time to work through it so we know all the facts before we vote on a person who is up for a lifetime job,” McConnell said.

The Senate Judiciary Committee is scheduled to take up the nomination on July 13. Republicans have complained bitterly about the timetable for considering the nomination. Majority Leader Harry Reid (D-Nev.) is aiming for a floor vote before the Senate breaks in August.

Sotomayor served on the group’s board of directors from 1980 to 1992. Conservatives opposed to her nomination have seized on a 1981 memo signed by her and two other directors of the group, which is now called LatinoJustice PRLDEF. In it, the directors argued against reinstating the death penalty in New York state, making the case that capital punishment is racist because it is disproportionately imposed on minorities.