Washington ? Chief Justice nominee John Roberts said Thursday there is no room for ideologues on the Supreme Court, declaring an “obligation to the Constitution” and to no other cause as he concluded three grueling days of confirmation testimony.

“If the Constitution says that the little guy should win, the little guy’s going to win in court before me,” Roberts told the Senate Judiciary Committee. “But if the Constitution says that the big guy should win, well, then the big guy’s going to win.”

Roberts’ confirmation as successor to the late Chief Justice William H. Rehnquist appears secure, the only question the size of his vote total and in particular his Democratic support. The Judiciary Committee is to vote its recommendation next week.

Roberts’ views on abortion – and whether he would vote to overturn a landmark 1973 ruling on the issue – hung uncertainly over the hearings from beginning to end. “That’s the big speculative question,” summed up Sen. Arlen Specter, R-Pa., and the committee chairman moments after he declared the proceedings closed.

The White House and Republican leaders hope for approval by the full GOP-controlled Senate in time for the 50-year-old appeals court judge and former Reagan administration lawyer to take his seat on the opening day of the court’s term on Oct. 3.

Conservatives pronounced themselves satisfied as Roberts wrapped up his appearance before the committee.

“His testimony on the right to privacy mirrored that of Clarence Thomas during his Supreme Court confirmation hearing,” read a memo circulated by Leonard Leo and Jay Sekulow, two conservatives who lead organizations working to clear the way for confirmation.

The right to privacy is the underpinning of the right to abortion, and Thomas has voted as a member of the high court to overturn the 1973 ruling that established a constitutional right to abortion.

In his testimony earlier in the week, Roberts said he believed the Constitution provides a right to privacy. But he offered no hint on how he would come down on the abortion issue, which is expected to come before the court in the coming year.

Despite pressure from civil rights and other liberal groups to oppose the nomination, some Democrats who questioned Roberts closely said they remained undecided.

After two largely futile days of trying to learn Roberts’ views on controversial issues, Democrats spent much of their final round of questioning trying to determine what Sen. Dick Durbin, D-Ill., called his “core values.”

“I think if you’ve looked at what I’ve done since I took the judicial oath, that should convince you that I’m not an ideologue,” Roberts said after Sens. Dianne Feinstein, of California, and Charles Schumer, of New York, asked him to say what kind of justice he would be.

“And you and I agree that that’s not the sort of person we want on the Supreme Court,” added the appeals court judge.