Dumbed-down version here:

The right to work, for example, is fundamentally different from the right (entitlement) to a job; the right to marry does not entitle me to a spouse; the right to free speech does not entitle me to an audience.

Whole thing here, which I really, really recommend, especially for those of you who want to get the historical basis and, moreover, hear a contemporary defense (via Cass Sunstein… blech).

H/T: Hit & Run