What if gays were straight?

The question is absurd—gays are defined as not straight, right?—yet increasingly central to the debate over civil-marriage rights. Here is how California’s Supreme Court put it in a key passage in its now-famous May 15 ruling that gay couples in California must be granted the right to marry, with no qualifications or euphemisms:

These core substantive rights include, most fundamentally, the opportunity of an individual to establish—with the person with whom the individual has chosen to share his or her life.