Judging by the liberal reaction, you would think the Supreme Court majority that struck down part of ObamaCare's birth-control mandate on Monday has suddenly imposed Shariah law. Yet as a matter of law rather than political opportunism, the narrow decision is an important vindication of religious liberty in this (still, blessedly) pluralistic constitutional republic.

Burwell v. Hobby Lobby challenged the Administration's requirement that all corporations cover contraception including abortifacients and sterilization in their...