Estrada was a career lawyer in the Soliciter General's office, not a political appointee. He also worked in the SG's office during Bush I. And I am sure you would find some things in the briefs he wrote during that time that you would not like. Just keep in mind, it was his job to represent and defend the position of his client, in this case, the Clinton Administration, not to argue his own beliefs and principles.
It was Reagan and Nixon "conservative" appointees who, along with the liberals, created judicial rules of judicial review of agency action that have placed federal agencies essentially beyond the rule of law, particularly in "scientific" (environmental) matters. Thus here in the Northwest, we live under bogus Endangered Species Act listings that, for all practical purposes, are immune from judicial review.