The administration intensified its efforts last year as President Bush's popularity and Republican support eroded heading into a midterm battle for control of Congress, which the Democrats won.

Facing nationwide voter registration drives by Democratic-leaning groups, the administration alleged widespread election fraud and endorsed proposals for tougher state and federal voter identification laws. Presidential political adviser Karl Rove alluded to the strategy in April 2006 when he railed about voter fraud in a speech to the Republican National Lawyers Association.

Questions about the administration's campaign against alleged voter fraud have helped fuel the political tempest over the firings last year of eight U.S. attorneys, several of whom were ousted in part because they failed to bring voter fraud cases important to Republican politicians. Attorney General Alberto R. Gonzales could shed more light on the reasons for those firings when he appears today before the Senate Judiciary Committee.

Civil rights advocates contend that the administration's policies were intended to disenfranchise hundreds of thousands of poor and minority voters who tend to support Democrats, and by filing state and federal lawsuits, civil rights groups have won court rulings blocking some of its actions.

Justice Department spokeswoman Cynthia Magnuson called any allegation that the department has rolled back minority voting rights "fundamentally flawed."

She said the department has "a completely robust record when it comes to enforcing federal voting rights laws," citing its support last year for reauthorization of the 1965 Voting Rights Act and the filing of at least 20 suits to ensure that language services are available to non-English-speaking voters.

The administration, however, has repeatedly invoked allegations of widespread voter fraud to justify tougher voter ID measures and other steps to restrict access to the ballot, even though research suggests that voter fraud is rare.

Since President Bush's first attorney general, John Ashcroft, a former Republican senator from Missouri, launched a "Ballot Access and Voter Integrity Initiative" in 2001, Justice Department political appointees have exhorted U.S. attorneys to prosecute voter fraud cases, and the department's Civil Rights Division has sought to roll back policies to protect minority voting rights.

On virtually every significant decision affecting election balloting since 2001, the division's Voting Rights Section has come down on the side of Republicans, notably in Florida, Michigan, Missouri, Ohio, Washington and other states where recent elections have been decided by narrow margins.

Joseph Rich, who left his job as chief of the section in 2005, said these events formed an unmistakable pattern.

"As more information becomes available about the administration's priority on combating alleged, but not well substantiated, voter fraud, the more apparent it is that its actions concerning voter ID laws are part of a partisan strategy to suppress the votes of poor and minority citizens," he said.

Former department lawyers, public records and other documents show that since Bush took office, political appointees in the Civil Rights Division have:

Approved Georgia and Arizona laws that tightened voter ID requirements. A federal judge tossed out the Georgia law as an unconstitutional infringement on the rights of poor voters, and a federal appeals court signaled its objections to the Arizona law on similar grounds last fall, but that litigation was delayed by the U.S. Supreme Court until after the election.

Issued advisory opinions that overstated a 2002 federal election law by asserting that it required states to disqualify new voting registrants if their identification didn't match that in computer databases, prompting at least three states to reject tens of thousands of applicants mistakenly.

Done little to enforce a provision of the 1993 National Voter Registration Act that requires state public assistance agencies to register voters. The inaction has contributed to a 50 percent decline in annual registrations at those agencies, to 1 million from 2 million.

Sued at least six states on grounds that they had too many people on their voter rolls. Some eligible voters were removed in the resulting purges.