He became Dean of Admissions of Georgetown Law in 1991 and was Dean of Admissions at the Georgetown Public Policy Institute (now the McCourt School of Public Policy) 2002-2016.

His responsibilities include providing advice for graduate programs at Georgetown University and overseeing the JD, LLM, and SJD Programs, which receive over 13,000 applications annually.

In 2006, Dean Cornblatt was named Associate Vice President for Graduate Enrollment for Georgetown University.

In 2018, he began the Early Outreach Initiative, a program designed to encourage high school students in underserved communities to think about a career in law. That program now involves forty high schools and one thousand students.