 From 2002-2004 Rosenkranz served as an attorney-advisor at the Office of Legal Counsel in the U.S. Department of Justice.In 2016 he served as Senior Advisor on Legal Policy and Constitutional Law for candidate Marco Rubio during Rubio's 2016 election campaign.He had previously been a member of 2008 presidential candidate John McCain's Justice Advisory Committee during the United States presidential election of 2008.