Facing an uphill battle over the nomination of Judge John G. Roberts Jr. to the Supreme Court, Democrats plan to challenge President Bush's nominee on economic, social and regulatory issues, hoping to use the confirmation process to highlight their differences with the Republicans and exploit them for future electoral gains.

The emerging Democratic strategy, described by Senate leaders and their aides, seeks to turn Bush's request for an orderly and deliberative confirmation process into a go-slow approach this summer designed to head off any presumptive talk of confirmation for Roberts before his hearings begin, probably soon after Labor Day.

Many Democratic strategists concede that Bush won the opening round of the confirmation battle, through his choice of a nominee who has been praised for his intellect and temperament and by a skillful unveiling that kept everyone guessing about the nominee's identity until an hour or so before Bush and Roberts appeared in the East Room of the White House.

"We were playing basketball blindfolded," said an aide to a senior Senate Democrat, who asked not to be identified to speak freely about internal planning. "The other side knew what moves they were making and we were necessarily reacting. . . . We quickly realized this was a candidate who needed further scrutiny. It would have been unrealistic to come out blasting John Roberts. It was time to hold our fire."

In that sense, the Democratic strategy remains a work in progress. The first goal of Senate Minority Leader Harry M. Reid (Nev.) has been to maintain a united front of neutrality among his Democratic colleagues and to avoid falling into what they see as a GOP-laid trap to vilify Roberts immediately and appear obstructionist and extreme.

Privately a number of Democrats see little likelihood that Roberts will be denied a seat on the court as the successor to retiring Justice Sandra Day O'Connor, unless something dramatic turns up in the review of Roberts's life and record. But party strategists and congressional aides said the hearings on Roberts nonetheless will provide a high-profile forum for a larger philosophical debate with Republicans.

Senate Democratic leaders have urged their colleagues to remain publicly neutral on the nomination until the minority staff of the Judiciary Committee can excavate Roberts's record during the August congressional recess. Their hope is that between now and then, they will develop the ammunition to assure a tough set of hearings for Roberts in the fall.

Sen. Patrick J. Leahy (Vt.), ranking Democrat on the Senate Judiciary Committee, described in an interview the strategy as realistic if neither dramatic nor confrontational. "I've urged some members on our side who've never been through Supreme Court hearings, 'Hold on, watch the hearings. You'll have a far better idea of who this person is,' " he said.

But Leahy suggested that the Democrats' response to Roberts is not an indication that the nominee will have an easy time in the confirmation hearings. Leahy said that, even without having had an opportunity to fully explore Roberts's record, he already has serious questions about abortion and states' rights vs. federal power.

"We have the most activist Supreme Court in my lifetime, in striking down congressional enactments, whether in environmental laws or violence against women act, child safety. I want to know his views on those subjects. Are we reaching the point where the [Constitution's] commerce clause is totally gutted? I want to go into it," Leahy said.

The two sides sparred yesterday over the Democrats' plan to request documents covering Roberts's tenure in the administrations of Ronald Reagan and George H.W. Bush. Former Republican senator Fred D. Thompson (Tenn.), who is shepherding the nomination through the Senate on behalf of the White House, said the administration would oppose such a request, citing attorney-client privilege.

"We hope we don't get into a situation where documents are asked for that folks know will not be forthcoming and we get all hung up on that," he said on NBC's "Meet the Press."

Attorney General Alberto R. Gonzales said on "Fox News Sunday" that this and other White Houses were reluctant to share such information and promised only to consider any Democratic requests. Leahy, on ABC's "This Week," dismissed that argument as a "red herring" and said Democrats would press the administration on the issue.

Democrats face some difficult choices, individually and collectively, as they prepare for the upcoming battle, beginning with the issue of abortion. Senate Democrats have signaled their desire to broaden the challenge to Roberts and not to make his confirmation a debate about the future of Roe vs. Wade, which establishes a woman's right to an abortion. But that could frustrate some of the Democrats' most important constituency groups.

Democratic strategists fear that party activists could rebel if Senate Democrats fail to make abortion a central issue. "Women know what's at stake here, and they will make their voices heard during the process and will make their voices heard at the ballot box next November," said Ellen Moran, executive director of Emily's List.

Presidential politics also will play a role in the upcoming debate, with Democratic senators contemplating a run in 2008 faced with a choice of opposing Roberts to placate left-leaning constituencies that will be important in the nomination battle or supporting Roberts to appear less obstructionist and therefore more appealing to swing voters in a general election.

That group includes Sens. Hillary Rodham Clinton (N.Y.), John F. Kerry (Mass.), Joseph R. Biden Jr. (Del.), Evan Bayh (Ind.) and Russell Feingold (Wis.). Kerry has been the most outspoken in criticizing Roberts, but it is Clinton whose vote is likely to draw the most interest.

Earlier this year Clinton talked about looking for ways to find common ground on the abortion issue, a move widely interpreted as emphasizing her centrist credentials. But the speech that drew such attention was also a ringing endorsement of preserving the right of women to have abortions. As a former first lady, she has a White House perspective on the importance of elections and the latitude a president should have in naming justices to the high court.

Leahy jokingly dismissed the notion that Democrats have a grand strategy but made clear that he believes the confirmation hearings will be illuminating. An aide to another Democratic senator put it this way: "At the end of the day, we don't know what will happen with Roberts. At the very least, we will show what Democrats stand for."

Sen. Harry M. Reid (D-Nev.), right, has promoted a united front of neutrality toward Supreme Court nominee John G. Roberts Jr., left.