On the Family and Medical Leave Act’s 20th anniversary, it is impossible to overstate the law's value to working families and the dramatic impact it has had on public schools, educators, nurses, public employees and other professionals. Since the FMLA's enactment, more than 50 million workers have been able to take job-protected time off when they need it most: for the care of a newborn, a newly adopted child or a family member who is seriously ill. When a school-age child gets sick, the FMLA allows a parent to keep the child at home so the boy or girl won't infect other students, which in...