Special Section: Elena Kagan
"The American people expect a justice who will impartially apply the law, not one who will be a rubberstamp for the Obama administration or any other administration," McConnell said in a written statement one day after Kagan, 50, wrapped up three days of testimony before the Senate Judiciary Committee.
(Note: South Carolina Republican Sen. Lindsey Graham, a member of the Judiciary Committee, is expected to appear on CBS' "Face the Nation" Sunday.)
Democrats hold a 59-41 majority in the Senate, and Kagan's confirmation is widely viewed as a certainty, barring an unexpected decision by Republicans to try and prevent a final vote. The Judiciary Committee is scheduled to vote on the appointment on July 13.
Kagan served as an aide in President Clinton's White House and is currently solicitor general in President Obama's Justice Department. She testified this week she would be able to put her political views aside if confirmed to the high court, and make rulings based on the Constitution.
In a written statement, McConnell quoted Kagan as telling the Senate Judiciary Committee this week it is "difficult to take off the advocate's hat and put on the judge's hat."
The statement added, "That difficulty is particularly acute for someone like Ms. Kagan, who has spent so much of her adult life practicing the art of political advocacy rather than practicing law."
Sen. Orrin Hatch of Utah, a senior Republican and member of the committee that conducted confirmation hearings, also , as did Sen. Lisa Murkowski of Alaska, who holds a leadership position.
Hatch voted last year to confirm Kagan as solicitor general, a post in which she has appeared before the Supreme Court representing the administration.
But he said a Supreme Court nominee needs "both legal experience and, more importantly, the appropriate judicial philosophy." And he said that "General Kagan regrettably does not meet this standard."
Murkowski said Kagan also did not give Americans any idea how she will approach "difficult cases" as a justice.
In the past five years, confirmation proceedings for Supreme Court nominees have shown a decided partisan tinge.
Chief Justice John Roberts, appointed by President George W. Bush, was confirmed 78-22 in 2005, and Democrats cast all the votes in opposition. The following year, Justice Samuel Alito was approved 58-42, with all but four Democrats opposed.
Mr. Obama's first pick for the court, Justice Sonia Sotomayor, was approved last year on a vote of 68-31. All of the votes in opposition were cast by Republicans.
More Kagan Coverage
Washington Unplugged: Analysis of the Kagan Hearings
Funniest Moments from the Kagan Hearings