The Americans with Disabilities Act, or ADA, forbids employment discrimination against individuals with disabilities.

For example, imagine that a construction worker had severe asthma. During periodic asthma attacks, the airways in the worker’s lungs would swell and restrict his breathing to a potentially fatal extent. The attacks could be triggered by stress, physical exertion, and even laughing too hard. The worker carried a medicated inhaler to reopen his airways when his attacks flared up....