According to another former senior ICE official, who is not authorized to speak publicly, the reasons are often prioritization and control.
“There’s only so, so many nominees that can get through, and if it’s a tight Congress where it’s going to be hard to get nominees through that, it can basically fall off the list of prioritization if there’s general happiness with acting [directors],” the official said.
The official added that some secretaries or administrations may prefer acting directors over political appointees because they believe the head of the department can exert more control over them.
“Senate-confirmed directors have a little bit of independence, because the Senate has said ‘we trust you, we’re empowering you to do this job,’” the official said. “In some cases, there may not be an obvious or a good candidate. Or there may be a sense that because the DHS mission ICE mission is so unique that it’s better to have acting [directors] whom the agency employees know and trust.”