As Congress and state governments have multiplied the list of protected classes, things have gotten messier. Is it really always wrong to try to hire a younger worker who can stick around for more years? Isn’t it legitimate for a law firm to assume a childless unmarried worker will be more available than a family man for the late nights a tough case might demand?

You may not agree with the boss’s decisions. You may think he’s cold-hearted. Similarly, you may find the sexual ethics of the Catholic Church impossibly stodgy.

But that doesn’t mean the federal government should always be involved. Not everything that’s wrong should be illegal. Sometimes these federal intrusions backfire: Studies have shown that employers are less likely to hire from protected classes, because firing that person is more legally perilous. Also, as Cato’s Walter Olson explains, expanding protected classes ties up the workplace with lawyers and litigation.

White racism in the 1960s was so widespread and so destructive that Congress decided it had to intervene. ENDA could remedy cases of unjust discrimination against gays — but in the process, it would make gays more expensive to hire, punish legitimate employer preferences and add to the stultifying accretion of government intrusion in private affairs.