WASHINGTON -- Senators on Tuesday began sparring over Elena Kagan's qualifications to be the next justice on the U.S. Supreme Court, but with her confirmation virtually assured, the debate largely served to highlight the rancorous divide between Democrats and Republicans in advance of this year's congressional elections.

With a floor vote expected this week, Kagan appears set to receive fewer yes votes than Justice Sonia Sotomayor did a year ago. Kagan, 50, was nominated by President Barack Obama in May to replace the retired Justice John Paul Stevens.

As U.S. solicitor general, Kagan represents the government before the Supreme Court, but her career largely has been spent outside the courtroom. She served as a lawyer and domestic policy adviser in the Clinton White House, and for almost six years headed the faculty at Harvard Law School.

Since she was chosen, Republicans have cast Kagan as an inexperienced, progressive political operative who would work to preserve the president's policy agenda once on the high court, rather than serve as objective jurist.

"She is young, but her philosophy is not," said Jeff Sessions of Alabama, the top Republican on the Senate Judiciary Committee, noting that Kagan could serve on the court for more than 35 years.

Her supporters, on the other hand, painted Kagan as a brilliant legal mind and a fair-minded moderate who will build consensus at the center of the court.

Kagan "will do her best to consider every case impartially, modestly, with commitment to principle and in accordance with law," said Democrat Patrick Leahy of Vermont, chairman of the Judiciary Committee.

At least five Republicans, including South Carolina Sen. Lindsey Graham, have indicated they will support her, enough to ward off a filibuster. One Democrat, Ben Nelson of Nebraska, has expressed his opposition, but in doing so he said he would not back any attempt to block the vote.