Fred Schwarz summarizes one good reason in the latest print version of National Review:

Anyone old enough to remember LBJ?s civil-rights laws, and the many other reform measures enacted from the Great Society to the present, has learned two things: (1) A federal bureaucracy must either grow or die; and (2) a federal bureaucracy never dies. As the abuses that a law was designed to fight are eliminated, the enforcement apparatus does not shrink to match; instead it expands and finds new abuses ? and when those run out, it starts inventing them.