From the day he assumed the presidency, Joe Biden has aggressively removed Donald Trump’s appointees from the executive branch to prevent them from sabotaging his administration. Biden’s termination of high-profile Trump holdovers, like the union-busting Peter Robb, has attracted the most attention. But the president has also fired holdovers who tried to “burrow in” to obscure agencies, many of whom were installed in the final weeks of Trump’s term. One such holdover, Roger Severino, promptly sued Biden after the president removed him and three fellow Trump appointees from the Admin...