America's "failing education system" has become a cliché of contemporary journalism — and it's most often blamed on the teachers. Union rules are said to protect the worst, while low salaries, crowded classrooms and unequal resources make it hard to retain the best. Disputes about standardized testing and the Common Core Curriculum have teachers caught in the middle. Teaching was once seen as a noble profession. We hear how that view has changed over time.
(This discussion originally aired on September 2, 2014.)