[7] Her maternal grandparents emigrated from Aidone, Sicily and her paternal family roots can be traced to Coreno Ausonio in the Lazio region of Italy.

[9] Duke served as Under Secretary of Homeland Security for Management at the department under both presidents George W. Bush and Barack Obama from July 2008 to April 2010.

[13] On January 30, 2017, President Donald Trump announced that he would nominate Duke as United States Deputy Secretary of Homeland Security.

In September 2017, in the wake of Hurricane Maria, Duke made the decision to waive the Jones Act for ten days, which requires goods shipped between points in the U.S. to be carried by vessels built, owned, and operated by Americans.

[24][25] In a July 2020 interview with The New York Times, after her tenure had ended, Duke criticized Trump's and his administration's approach and rhetoric on immigration-related issues.