It looked like a normal first day of school at Patria Libre elementary. Uniformed kids sporting brand-new backpacks with their favorite cartoon characters — Dora the Explorer, Hello Kitty, the "Frozen" heroines — reunited with classmates and sang the national anthem.
But that's far from normal in Oaxaca, a Mexican state where teachers' strikes and protests cost the average student 50 days out of the 200-day academic calendar last year, according to federal education officials.
Year after year, protesting teachers have blocked highways and cut off oil refineries. Residents of the capital have fled rocks and tear gas from . . .
