A high-profile panel that included Gov. Arnold Schwarzenegger and Washington, D.C., Public Schools Chancellor Michelle Rhee met in Sacramento on Tuesday evening and discussed pitfalls in the nation’s education system. Most of the members of the panel, which also included Sacramento Mayor Kevin Johnson, Los Angeles Mayor Antonio Villaraigosa and an official with the Bill & Melinda Gates Foundation, said state and national teachers’ unions have made efforts to halt education reforms. The panel held its discussion after a screening of “Waiting for Superman,” filmmaker Davis Guggenheim’s new documentary about education reform. About 200 people gathered for the screening, including special gu