Interest groups troubled by John Roberts' (search) record are blitzing Internet sites and airwaves in hopes of building public support for the Senate to take a close look at the Supreme Court nominee.

To keep a spotlight on Roberts during the summer doldrums, the initiative includes visits to newspaper editorial boards, rallies, petition drives and the first television ads purchased by liberal groups. Confirmation hearings begin Sept. 6, just days after senators return from their monthlong break.

Many of these organizations took a low-key approach after President Bush's selection of Roberts two weeks ago but have become more vocal in light of documents they say show he is hostile to civil rights.

Some conservative groups said Monday they are prepared to defend Roberts by spending millions of dollars in "key battleground states" in which senators are up for re-election in 2006.

"We're playing an aggressive defense," said Gary Marx, executive director of the Judicial Confirmation Network.

IndependentCourt.org, a liberal coalition of 75 organizations including the Alliance for Justice and People for the American Way, began airing ads this week as part of its "Right to Know" drive. It called on the White House to stop "withholding important documents from senators."

The 30-second ads, which begin and end with a shot of the Supreme Court, state that Americans need "straight answers" on Roberts' stance on "basic rights" and "fundamental freedoms."

"Before the Senate votes to give John Roberts a powerful lifetime appointment to our nation's highest court, Americans have a right to know what kind of Supreme Court justice he will be," Wade Henderson, executive director of the Leadership Conference on Civil Rights, said in an interview.

"The documents that the White House has produced are just the tip of the iceberg and yet they suggest a very disturbing and very different picture of Roberts' record," Henderson said.

The White House agreed to release thousands of documents from Roberts' tenure in the White House counsel's office in the mid-1980s as well as his time working as an attorney in the Reagan Justice Department from 1981-82.

Many of the memos paint a portrait of a politically savvy attorney who encouraged his bosses to restrict affirmative action, Title IX (search) sex discrimination lawsuits and prisoner appeals in federal court, which he said "made a mockery of the entire criminal justice system."

Democrats on the Senate Judiciary Committee are now seeking thousands more documents, including material requested Friday related to 16 cases in which Roberts is believed to have participated when he served as a top deputy in the solicitor general's office from October 1989 to January 1993.

The cases involve politically sensitive issues -- school desegregation, abortion, the death penalty and school prayer -- that Democrats say will shed light on the nominee's views.

Judiciary Committee staff were continuing to review documents this week, and Democrats were awaiting a response from Attorney General Alberto Gonzales regarding the additional material requested, said Tracy Schmaler, a spokeswoman for Democrats on the committee.

In their campaign, interest groups said they were targeting states that had their most members, as well as the home states of the 18 members of the Judiciary Committee and other key swing senators.

People for the American Way President Ralph Neas said he was meeting this week with members and newspaper boards in California -- the group's largest membership base -- to call for senators not to take a position on Roberts' nomination until after the confirmation hearings.

NARAL Pro-Choice America, which opposes Roberts' nomination, has launched grassroots campaigns in Georgia, Iowa, Minnesota, Montana, New Jersey, New Mexico, New York, Ohio, Oregon and Washington state, in many cases going door-to-door to generate letters and calls to senators.

The group wants senators to question the nominee hard on whether the federal appeals judge believes the landmark case of Roe v. Wade (search), which made abortion legal nationwide, should be overturned, said Nancy Keenan, NARAL's president.

Moveon.org also has set up an online petition to tell senators to oppose the "right-wing ideologue," while the Leadership Conference on Civil Rights has a Web site allowing people to post pictures of themselves with protest signs.

According to an AP-Ipsos poll last month, 59 percent of Americans said they hadn't heard enough about Roberts to form an opinion about him, while 25 percent said they viewed him favorably and 14 percent unfavorably. Just over half of those polled also said they wanted to know Roberts' position on abortion.

Sean Rushton, executive director of the conservative Committee for Justice, said his group will be targeting Democratic senators in the red states of Arkansas, Louisiana, Nebraska, Colorado, Indiana, and North and South Dakota later this month with radio ad buys.

"If interest groups are really attacking the nominee in a harsh way, you'll see us come after them," Rushton said.