Arizona and Delaware extend that by forbidding businesses from refusing to hire applicants or disciplining employees on the basis of drug tests that reveal marijuana components or metabolites.

FORBES: 'What Were They Smoking?' States' Legalizing of Marijuana Means Headaches for Employers

Mr. Akhmechet also found he couldn't hire prized applicants without raising everyone else's salaries or getting them to agree to exceptions, he says.

WSJ: Transparency at the Office: Psst...This Is What Your Co-Worker Is Paid

The EEOC is confident that its guidance will boost minority hiring, but studies published in the University of Chicago Legal Forum and the Journal of Law and Economics have found that businesses are much less likely to hire minority applicants when background checks are banned.

WSJ: James Bovard: Perform Criminal Background Checks at Your Peril

He says he often didn't hire the most skilled applicants.

FORBES: Business Basics

The city also cited the school's decision to re-hire Mr. Calderon-Melendez as its CEO without considering other applicants and without discussing concerns of prior board members about Mr. Calderon-Melendez.

WSJ: Charter Network Facing Closure