WASHINGTON — With an eye on the partisan fight ahead over the next Supreme Court vacancy, a Senate panel yesterday voted 13-5 to recommend that the full Senate confirm the nomination of John G. Roberts as chief justice.

Besides the 10 Republicans on the Senate Judiciary Committee, three of the eight Democratic members broke ranks to support Roberts, who at age 50 could lead the court for the next three decades.

Two key Democrats on the committee who had said they were struggling over whether to support Roberts – Sen. Charles Schumer (D-N.Y.) and Sen. Dianne Feinstein (D-Calif.) – decided to vote against him, worried that he might be an ideologue and that he might not uphold women’s rights.

But in a surprise to liberal activists, Sen. Russell Feingold (D-Wis.) voted for Roberts, as did Sen. Herb Kohl (D-Wis.) and Sen. Patrick Leahy (D-Vt.).

“Some of the voting today was calculated to impact on the next nomination,” Sen. Arlen Specter (R-Pa.), the committee chairman, said afterward.

Some Democrats voted yes to put themselves in a better position to oppose the next nominee, he said, and others voted no to warn the White House to choose someone acceptable to a “broad spectrum of senators.”

Roberts’ nomination now goes to the Senate floor Monday, with a full Senate vote by Thursday, Specter said.

Roberts’ confirmation is considered a foregone conclusion.

Sen. Hillary Rodham Clinton (D-N.Y.), a potential 2008 presidential contender, said yesterday that she will oppose the nomination. In prepared remarks, she said, “Desire to maintain the already fragile Supreme Court majority for civil rights, voting rights and women’s rights outweighs the respect I have for Judge Roberts’ intellect, character and legal skills.”

President George W. Bush could announce his choice to replace moderate Justice Sandra Day O’Connor, who is retiring, as soon as next week.

Because of her role as a swing vote, Specter said, “The next confirmation hearing is going to be very contentious.”

In explaining their votes on Roberts yesterday, senators talked not only about his qualifications, but also about how they evaluate a nominee to the court.

“I believe that the president does enjoy some deference here,” said Sen. Lindsay Graham (R-S.C.) Graham said the central issue is whether the Senate will allow Bush “to fulfill a campaign promise … to nominate a well-qualified strict constructionist to the court.”

Feingold agreed, saying the “central reason” he broke with other Democrats to vote for Roberts is that he expects the same deference to the president and his choice for the high court “when my party retakes the White House.”

But the five Democrats who voted against Roberts said the central issue instead is whether he intends to roll back rights.

Feinstein, the only woman on the committee, said a court candidate must pass this bar: “Once someone has earned a right they should not lose that right.”

Based on Roberts’ memos as a Reagan administration attorney in the 1980s and his testimony last week, Feinstein said, “He didn’t cross my bar.”

Since 2001, Schumer has attacked Bush’s vow to appoint justices in the mold of Justices Antonin Scalia and Clarence Thomas as an ideological courtpacking scheme.

Roberts is “brilliant” and he might not be an ideologue, Schumer said. But because of a “reasonable danger that he will be like Judge Thomas,” Schumer said he had to vote no.