Associate Hospital Epidemiologist, Johns Hopkins Hospital, Professor of Pediatrics at John Hopkins University, School of Medicine

Professor of Biology and Chemistry at Caltech, Division of Biology and Biomedical Engineering

Professor of Biology and Chemistry at Jacksonville University in Jacksonville, FL

Assistant Professor of Emergency Management at Massachusetts Maritime Academy in Boston, MA

Professor or Microbiology and Infectious Diseases at Boston University, School of Medicine

Interim Dean, Tufts University School of Medicine; Chief Academic Officer, Tufts Medicine; Infectious Disease Physician, Tufts Medical Center at Tufts Medical Center

Co-Director, Division of Infectious Diseases, Associate Professor of Medicine and Molecular Microbiology at Washington University of St. Louis, School of Medicine

Founding Director at U.S. Immigration Policy Center, UCSD

Director of Research, U.S. Programs at Migration Policy Institute

Senior Demographer at Pew Research Center

Immigration Justice Campaign Director at American Immigration Council

Faculty Affiliate at U.S. Immigration Policy Center, UCSD

Director of Immigration Law and Policy Research at Economic Policy Institute

Deputy Legal Director and Director of Center for Democracy at American Civil Liberties Union (ACLU)

Founding Director at U.S. Immigration Policy Center, UCSD

Ambassador at American Immigration Council

Executive Director at Center for Immigration Studies