For years following Hurricane Katrina (for those of you might not have been alive and working back then...) there followed for a number of years an effort and debate to get the Federal Emergency Management Agency (FEMA) out of DHS. I likely added fuel to that fire with this Washington Post Op-ed I authored Destroying FEMA and published the day after the levee's broke in New Orleans. I like to remind people the hurricane was near the end of August and I first penned the op-ed and submitted it in July. Call me a soothsayer, but the results were predictable.
When DHS was established it was total chaos for the agencies that were all brought together under its umbrella. While they learned to be part of a larger single department, Congress never did reorganize and the agency/DHS has legislative oversight from a plethora of congressional committees, all with their own ax to grind.
It is possible, although highly unlikely, that a new administration will take the drastic action to 'put asunder' what has been cobbled together. There are "plenty of other fish to fry" with a COVID-19 recession all but declared, the virus to contend with and international relationships to be mended. And many more actions needed to restore confidence in national governance.
I believe will take a future catastrophic failure of epic proportions for real traction to happen on dismantling DHS.