One of the Trump administration's top immigration policy staffers is leaving the Department of Homeland Security to join the attorney general's office at the Department of Justice -- reuniting him with Jeff Sessions.
Gene Hamilton, a senior counselor to the Homeland Security secretary since January and top immigration policy expert for the administration, confirmed the move to CNN.
Hamilton's departure will be a blow to Homeland Security's policy shop, sources familiar with the situation said. The agency is tasked with managing the vast majority of the administration's immigration portfolio.
But the move will reunite Hamilton, a former Sessions staffer, with the Cabinet's strongest immigration policy hardliner, an early supporter of President Donald Trump who has been a key proponent of his aggressive immigration agenda from his perch at DOJ.
Hamilton was a general counsel for Sessions on Capitol Hill and will work directly with the attorney general in his new role. The switch is tentatively expected to begin next week, the sources said.
Two sources familiar with his actions told CNN that Hamilton first announced the move October 13 in a staff meeting, but it took some time for it to be finalized.
After more than a week of waiting, sources familiar with the situation said, it required intervention by the highest levels of DHS and DOJ to press the White House personnel office to approve the move.
The back and forth with the White House, now run by former DHS Secretary John Kelly as chief of staff, and the agencies came to a head this week. The White House resisted making the change before the new secretary was in place, in part over concern over how it would be perceived, if it could be taken as a reaction to the nomination of a new secretary, and by who would replace Hamilton.
After the pushback, the personnel office finally relented late Wednesday evening, shortly before Hamilton's previously scheduled farewell gathering. As an indicator of how both agencies were supportive of his move, dozens attended the gathering, including the acting secretary, who had sent out the invitation for it herself.
DOJ declined to comment, saying it doesn't comment on personnel matters. The White House did not immediately respond to a request for comment.
"Gene has been a highly valued member of the secretary's senior staff," DHS spokesman Tyler Houlton said in a statement. "His deep knowledge of the issues the department handles and his dedication to supporting the frontline law enforcement officers of DHS will be missed. We look forward to working closely with Gene in his new role at the Department of Justice."
Other sources also lamented the departure as a blow to DHS.
One of the sources, who is familiar with immigration issues, said the departure was a "big loss" for the agency. Hamilton was the key staffer liaising with the Hill and the White House on implementing the President's immigration agenda.
"There is no one as steeped in these issues and who has been for such a long period of time," the source said.
The move also came on the heels of the announcement of the nomination of Kelly's top staffer Kirstjen Nielsen to lead the department, but according to sources familiar, the departure was in the works before her announcement and was not driven by any animosity.
"I look forward to watching the department continue to thrive and succeed from a different role," Hamilton said when reached for comment. "I wish everyone the best and it's been a privilege."
While the move would take Hamilton out of the development of DHS immigration policies, where the secretary's office oversees components including Immigration and Customs Enforcement, Customs and Border Protection and US Citizenship and Immigration Services, DOJ under Sessions has been taking a stronger role in immigration policy during this administration.
Sessions himself remains a thought leader in the administration on the tough immigration agenda of the President, and DOJ manages the nation's Immigration courts.
Justice also is charged with representing the government in litigation -- which would include all the sanctuary cities litigation, DACA lawsuits and ongoing travel ban litigation.