President Bush on Friday formally sent to the Senate the nomination of John Roberts (search) for the Supreme Court, while officials said the Senate Judiciary Committee will begin confirmation hearings for Supreme Court nominee John Roberts (search) on Sept. 6.

A committee vote is expected Sept. 15, according to a Senate calendar obtained by FOX News. Full Senate floor debate is scheduled to begin by Sept. 26 at the latest. Sept. 29 is the last business day before the Supreme Court convenes for its new term on Oct. 3. The White House and Senate Republicans have demanded the new justice be in place by that time.

The Judiciary Committee chairman, Sen. Arlen Specter (search), R-Pa., was scheduled to hold a press conference Friday afternoon to announce the dates. Specter has indicated in the past that he could begin the hearings by Aug. 29 but many lawmakers said they had vacation plans and didn't want to cut the recess short.

While the hearing's format has not been announced, Democrats have been in discussion with Specter about getting at least 90 minutes each to question Roberts in committee on his judicial philosophy and paperwork, Republican sources said.

The Senate Judiciary Committee's ranking Democrat, Sen. Patrick Leahy (search) of Vermont, said that without a bipartisan document request agreement, he can't guarantee that Democrats will be ready to vote by the Sept. 29.

Meanwhile, Democrats on the Senate Judiciary Committee on Friday sent a letter to Attorney General Alberto Gonzales requesting information on 16 cases Roberts handled as a deputy solicitor general under President George H.W. Bush. Earlier this week, Senate Democratic Judiciary members sent a letter to President Bush containing a priority list of documents from the Reagan library in California.

Democrats deny they're merely on a fishing expedition as they demand the White House release more documents about Roberts than it has. Although Democrats have not even yet formally requested any such documents, the White House released about 75,000 pages earlier this week.

Democrat say they only want a few specific memoranda from Roberts' 1989 to 1993 tenure as deputy solicitor general. The White House, claiming attorney-client privilege, has said 'no,' and does not plan to negotiate on the issue. Democrats have signaled a willingness to accept as few as 20 specific documents from Roberts' time as solicitor general.

In another part of Washington, former Democratic senator and vice presidential candidate John Edwards (search) harshly criticized Supreme Court nominee John Roberts (search) Friday, calling him "a partisan for conservative causes."

Roberts, finishing his second week of visits with senators in search of confirmation votes, was being criticized from the sidelines in a speech that Edwards prepared for the American Constitution Society.

This came a day after Sen. Edward Kennedy (search) accused Roberts, 50, of having a questionable commitment to civil rights.

Although the complaints aired Friday were among the toughest yet since Bush picked Roberts for the high court, there still were differences of opinion within the Senate Democratic caucus. And there remained no hint of a filibuster.

In fact, some other Democrats have called Roberts "outstanding" and have said they'd been assured he wouldn't be a conservative activist on the court.

But a review of paperwork that Roberts drafted while he worked in the Reagan administration shows a "very different young lawyer at work, a partisan for conservative causes," said Edwards.

Edwards, a former North Carolina senator, voted to confirm Roberts' earlier nomination to the U.S. Court of Appeals for the District of Columbia when he was a member of the Senate Judiciary Committee two years ago.

"Someone who opposed efforts to remedy discrimination on the basis of sex and race," Edwards said in his prepared remarks. "Someone who opposed measures to protect voting rights ... The question now is, who is the real Judge Roberts?"

The same documents "certainly raise some questions in my mind about his commitment" to civil rights in general, Kennedy told reporters Thursday.

Some of Kennedy's Democratic colleagues are praising Roberts' academic and legal credentials. They expect little negative material to turn up before the start of Senate Judiciary Committee hearings for the 50-year-old federal appeals court judge.

"I was so pleased to meet such an outstanding nominee," said Sen. Mary Landrieu, D-La. Added Sen. Ben Nelson, D-Neb.: "I don't see anything that's going to be disturbing" in his record.

Nelson, who is leaning toward approving Roberts' nomination, said Roberts assured him on Thursday that he would not bring an activist philosophy to the court if he is confirmed to replace retiring Justice Sandra Day O'Connor (search).

"He said he would not be an activist judge," Nelson said.

Roberts turned aside questions from reporters as he continued get-acquainted meetings with senators of both parties. "I don't think it's appropriate for me to answer questions outside of the Judiciary Committee," he said.

Kennedy is likely to put civil rights questions to Roberts at the committee hearings.

The senator was asked whether documents released by the White House showed Roberts was not as committed to civil rights as Kennedy would like. "I didn't reach that conclusion yet. But it does certainly raise some questions in my mind about his commitment," Kennedy said.

In one document, Roberts, then working in the White House, wrote that legislation designed to overturn a different Supreme Court ruling would "radically expand the civil rights laws to areas never before considered covered." He recommended against it.

In another, he wrote that the administration could "go slowly on housing legislation" without fearing political damage.

Democrats are demanding other paperwork from Roberts' time as principal deputy solicitor general during the administration of the first President Bush.

But the White House plans to deny access to those papers, citing the need "to preserve the attorney-client privilege for this administration" and in the future, according to presidential spokesman Scott McClellan.

The White House has released documents from Roberts' time as a special assistant at the Justice Department early in the Reagan administration. Officials have pledged to expedite release of records while Roberts was working in the White House counsel's office from 1983 to 1986.

Democrats are trying to come up with a limited request on the blocked documents. Kennedy said they would request documents "limited and targeted on cases related to the Constitution."

FOX News' Carl Cameron and The Associated Press contributed to this report.