at least from his resume:
Perez has spent his entire career in public service. He began his law career as a law clerk for Judge Zita Weinshienk of the United States District Court for the District of Colorado from 1987 to 1989.[14]
Perez spent 12 years in federal public service, from 1989 until 2001. He spent the bulk of his federal public service at the United States Department of Justice. He was a federal prosecutor for the Civil Rights Division of the Department of Justice from 1989 to 1995.[15] In so doing, he prosecuted and supervised the prosecution of some of the Department's most high profile civil rights cases, including a hate crime case in Texas involving a gang of white supremacists who went on a deadly, racially motivated crime spree directed at African Americans.[16] He later served as Deputy Assistant Attorney General for Civil Rights under Attorney General Janet Reno.[17] Among other responsibilities, Perez chaired the inter-agency Worker Exploitation Task Force, which oversaw a variety of initiatives designed to protect vulnerable workers.[18]
From 1995 until 1998, Perez served as Special Counsel to Senator Edward Kennedy, and was Senator Kennedy's principal adviser on civil rights, criminal justice and constitutional issues.[19] For the final two years of the Clinton administration, Perez served as the Director of the Office for Civil Rights at the United States Department of Health and Human Services.[20]
From 2001 until 2007, Perez was a professor at the University of Maryland School of Law, where he taught in the school's nationally recognized clinical law, and law and health program.[21] Perez was also a part-time member of the faculty at the George Washington University School of Public Health.[22]
http://en.wikipedia.org/wiki/Thomas_Perez