Teach for America at 25: With Maturity, New Pressure to Change

Teach for America's outsize reputation has always made it a lightning rod. In the early years, its critics were rooted in the education establishment: teachers unions, the big education schools and their leaders.

Lately attacks have come from a new and surprising source. Once an upstart and an outsider challenging an entrenched system, TFA now finds itself part of the establishment, assailed by a new generation.

A self-described TFA resistance movement has appeared, led by some of its own alumni.