Nearly a decade after the federal No Child Left Behind Act became law, standardized tests are still king in the nation's public schools. And the stakes of those exams are higher than ever for teachers and principals whose evaluations are linked to those scores.

The Obama administration has promoted such use of test score data -- as well as closing or restarting schools with chronically low scores -- as a tool to improve public education.

Thousands of people who think those policies are hurting public schools are making their way to Washington, D.C., for a Saturday rally outside the White House. The Save Our Schools March has star power behind it: actor Matt Damon has RSVPed as a speaker, and comedian Jon Stewart is making a video for the rally. Diane Ravitch and Pedro Noguera, scholars who have attained celebrity status in the education world, also are among the rally's headliners.

One of the galvanizing forces behind this three-day event is Anthony Cody, a former Oakland public middle-school