On Monday morning, President Obama announced his pick to replace outgoing Secretary Hilda Solis at the Labor Department: Thomas Perez, an assistant attorney general in charge of the Justice Department’s Civil Rights Division.

He was behind many of the big Justice Department cases of the last four years. Perez worked closely with Attorney General Eric Holder on several civil-rights cases in the president’s first term. Holder hopes to make accomplishments on civil rights part of his legacy at Justice. Perez’s Civil Rights Division oversaw the Justice Department objection to two similar laws that required voters to show a photo ID in Texas and South Carolina, saying the states did not adequately prove the laws comply with the Voting Rights Act. Both states filed lawsuits against the Justice Department in the U.S. District Court for the District of Columbia to restore their laws. The court agreed with the department’s objection to the Texas law, while it upheld South Carolina’s law, ruling, however, that it cannot go into effect until this year.

Labor loves him. Perez, a Harvard Law graduate, has a long history of working on labor issues. From 2007 to 2009, he served as the Maryland labor secretary under Gov. Martin O’Malley, before he was tapped for his current position at Justice. During his tenure, he helped write a reform package that was aimed at addressing the state’s foreclosure crisis. Perez has specialized in civil-rights law throughout his career, serving as a Justice Department attorney and a special counsel to the late Sen. Edward Kennedy. He also held two civil-rights positions in the Clinton administration.

Republicans, however, are quickly raising red flags about Perez’s spotty record. Sen. David Vitter promised to block Perez’s nomination until Congress gets some answers about a DOJ lawsuit against Louisiana that alleges the state agencies violated federal law by not providing voter registration forms to low-income voters, a case overseen by Perez, as well as concerning Perez’s role in the high-profile New Black Panther voter intimidation case:

“Thomas Perez’s record should be met with great suspicion by my colleagues for his spotty work related to the New Black Panther case, but Louisianians most certainly should have cause for concern about this nomination,” said U.S. Sen. David Vitter. “Perez was greatly involved in the DOJ’s partisan full court press to pressure Louisiana’s Secretary of State to only enforce one side of the law – the side that specifically benefits the politics of the president and his administration at the expense of identity security of each and every Louisianian on the voter rolls.”

In the 2011 letter, Vitter asked the DOJ to be consistent in their efforts to enforce the National Voter Registration Act. In a letter to Attorney General Eric Holder, Vitter highlighted that DOJ filed a lawsuit against Louisiana alleging the state has not complied with Section 7 of NVRA, yet has done nothing to enforce Section 8 in other states. Thomas Perez is specifically named in the letter…

And Sen. Chuck Grassley was not particularly impressed with Obama’s choice, either, via Katrina Trinko:

“Nominating somebody who is in the middle of a congressional investigation shows me that the President isn’t very serious about working together,” said Senator Chuck Grassley (R., Iowa) in a statement. “It appears that Mr. Perez may be at the heart of a decision by the Justice Department to make a quid pro quo deal with the city of St. Paul, Minnesota that ultimately led to the American taxpayer potentially losing hundreds of millions of dollars by declining to intervene in a False Claims Act case that career attorneys had signed off on. I’m looking forward to hearing his testimony, because there are a lot of tough questions he should answer for the American people, including those regarding St. Paul.”

In a September letter to attorney general Eric Holder, Grassley, then-chairman of the Judiciary Committee Lamar Smith (R., Texas), Oversight Committee chairman Darrell Issa (R., Calif.), and then-chairman of the Subcommittee on TARP, Financial Services and Bailouts of Public and Private Programs Patrick McHenry (R., N.C.) outlined why they believed Perez had been involved in a quid pro quo deal. The city of St. Paul was set to argue before the Supreme Court that its enforcement of the city’s housing code, which disproportionately affected minorities, did not violate discrimination laws — but abruptly decided not to do so, possibly because of a deal engineered by Perez.

The Obama administration might be trying to foist a bigger immigration-related role onto the Labor Department as that debate progresses (who knows what they’ll think of next with all of that “prosecutorial discretion”), and it’s looking likely that the minimum-wage battle is getting ready to intensify; I wouldn’t expect Republicans to let this one through without a pretty tough confirmation process.