Sen. Chuck GrassleyCharles (Chuck) Ernest GrassleyGrassley: 'Good chance' Senate panel will consider bills to protect Mueller Overnight Finance: CBO to release limited analysis of ObamaCare repeal bill | DOJ investigates Equifax stock sales | House weighs tougher rules for banks dealing with North Korea GOP state lawmakers meet to plan possible constitutional convention MORE (R-Iowa) says he needs to go back to the record to determine why he voted against Sonia Sotomayor's nomination to the appellate court in 1998.

Not until a reporter recently reminded him did Grassley realize he had voted against Sotomayor's nomination, the Iowa Republican told C-SPAN today.

"Evidently I was one of the 27 people that voted against her when she went on the Circuit," he said.

Grassley, who sits on the Judiciary Committee, said he'll go back and re-examine his stated reasons for opposing Sotomayor, but it shouldn't be taken as a sign that he'll necessarily vote against her this time around.

"And I don't want anybody to believe that I'm going to have that be a reason for me having my mind made up now," he added. "Because quite frankly, I'm going to have to go back and hopefully I gave a speech at the time, or there's something in the record of my rationale for the no vote at the time."