Enemies of limited government are an energetic, persistent bunch, and one of their most effective strategies to aggrandize state power is what I call "gapism." Here's how it works. Begin by uncovering some "gap" between haves and have-nots. Contemporary examples include differences in health care quality, life expectancy, educational attainment, home ownership, obesity, internet access, credit card fees, fresh produce in supermarkets, superior day care, salt and trans fat consumption, university faculty appointments, visits to national parks, corporate salaries, illegitimacy, home libraries, high school dropout rates, stock ownership, and countless other conditions. These discrepancies automatically become "a troubling problem." That...