Sen. Pat RobertsPat RobertsMembers help package meals at Kraft Heinz charity event in DC Dems mock House GOP over lack of women in healthcare meeting Perdue vows to be chief salesman for US agriculture abroad MORE (R-Kansas) became the first senator Thursday to go on the record to say that he would vote against Judge Sonia Sotomayor's nomination to the Supreme Court.

While many Republicans have opted to keep their powder dry, issuing statements about carefully reviewing President Obama's pick to join the high court, Roberts flatly stated he wouldn't support Sotomayor.

"I do not plan to vote for her," Roberts told radio host Chris Stigall on KCMO Talk Radio 710 this morning.

"I voted no in 1998. I did not feel she was appropriate on the appeals court," Roberts said. "Since that time, she has made statements on the role of the appeals court I think is improper and incorrect."

Other lawmakers have expressed similar complaints about Sotomayor, but no others have yet come out to state that they'll vote against her.