At Justice, Perez has reinvigorated a division tarnished by a political hiring scandal during President George W. Bush's administration and run for years by political appointees hostile to many of its long-term policies. He launched a record number of investigations into civil rights abuses and other misconduct at local police departments around the country. That includes a lawsuit last year accusing the office of law-and-order Arizona sheriff Joe Arpaio of racially profiling Latinos during a crackdown on illegal immigrants.
Perez also played a leading role in challenging laws in Texas and South Carolina that require voters to show photo identification in order to vote. A federal court later struck down the Texas law, saying it restricts minority voting rights, while another court delayed implementation of the law in South Carolina until after the 2012 election.
His nomination has broad support from labor and from the Latino community. Among those at the White House ceremony Monday were AFL-CIO President Richard Trumka and NAACP President and CEO Benjamin Jealous.
The nomination likely was delayed by the release last week of the Justice Department report. It found that Perez gave incomplete testimony to the U.S. Commission on Civil Rights when he said the department's political leadership was not involved in the decision to dismiss three of the four defendants in a lawsuit the Bush administration brought against the New Black Panther Party.
While the report concluded that Perez did not intentionally mislead the commission, it said he should have sought more information about the role of the agency's political leaders who participated in the decision to dismiss those charges.
Republican Sen. Charles Grassley of Iowa said Perez appeared to be "woefully unprepared to answer questions" from the Civil Rights Commission.
Other Republicans have cited his role in persuading the city of St. Paul, Minn., to withdraw a lending discrimination lawsuit from the Supreme Court. In exchange, the Justice Department declined to join two whistle-blower lawsuits against St. Paul that could have returned millions in damages to the federal government.
The St. Paul case had challenged the use of statistics to prove race discrimination under the 1968 Fair Housing Act, and Justice Department officials were concerned the court could strike down the practice.
Perez, once the top adviser to Sen. Edward Kennedy on civil rights, is a former career attorney at the Justice Department division he now leads.
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