People tried staying and being an "inside" ally during Trump's first term. In the end, it just helped his administration maintain a veneer of competency.
Leave. Let the institution fall. Collapse of the systems people rely on is the only way to gather overwhelming popular support to contain Trump's destruction.
Someone with the skills and knowledge to clean up 150-year old typographical errors in one particular table in the Social Security database system would probably provide more benefit to the taxpayers covering their salary by doing some other task.