President Barack Obama will nominate former top Defense Department lawyer Jeh Johnson on Friday to be the next secretary of Homeland Security, replacing Janet Napolitano, according to a senior administration official.

The administration is touting Johnson as a “critical member of the president’s counterterrorism team” and a trusted adviser, who assisted in a report that helped lead to the repeal of “don’t ask, don’t tell” in 2010 and worked on the legal overlap and coordination with the Department of Homeland Security and the Defense Department during disaster responses.

The post’s sprawling jurisdiction, particularly over the politically charged area of enforcement of immigration laws, is sure to make for interesting hearings in the Senate.