Alan Clayton, a Perez supporter, said the nominee's association with CASA would make it tougher for him to get Senate confirmation, describing the Maryland nonprofit as "very, very hard-core" on immigrant rights issues.
Perez "is going to get hit by the individuals who don't like pro-immigration policies," said Clayton, director of equal employment opportunity for the Los Angeles County Chicano Employees Association.
Todd Gaziano, a lawyer who directs the Center for Legal and Judicial Studies at the Heritage Foundation, a conservative think tank, said Perez also could suffer from lingering anger over Obama's failure to appoint Saenz, even though the groups that protested the decision later endorsed Perez.
"The bad blood in the water still may affect this guy's confirmation. It may affect the enthusiasm some people have" for Perez, said Gaziano, a member of the U.S. Commission on Civil Rights.
Affirmative action, a central focus of the confirmation fights of the 1990s, could also play a role.
"I was just reading a law review that Perez has written that was very favorable toward the use of racial preferences," said Clegg, an advocate of colorblind public policies.
Obama "has indicated that he's not entirely comfortable with racial preferences," Clegg said. Perez "may be more liberal than the president himself is."
The president has pledged to "reinvigorate federal civil rights enforcement" and prosecute more cases of housing and employment bias and voting discrimination against blacks. His budget contains an 18 percent budget increase for the civil rights division, which became a source of controversy during the Bush administration
An inspector-general's report released this year detailed efforts under President George W. Bush to replace career lawyers in the civil rights division with those with conservative Republican credentials. Obama has promised to "restore professionalism" to the division.
The first big challenge for Perez, who began his career in the office he's been picked to lead, would be to boost morale, said Hilary Shelton, director of the Washington office of the National Association for the Advancement of Colored People.
"Tom is somebody that I'm convinced knows how to repair that department," said Shelton, referring to Perez's background there, his years as an aide to Democratic Sen. Edward M. Kennedy and his work as the leader of Obama's transition team at the Justice Department.
