My problem with the all of the alleged political agendas in my school was that the chapter in my text book about Japanese internment was 12 pages, women and black people's service another 12 or so, but the ENTIRE history of the American military in the pacific was like 2, and then 12 more pages on why we shouldn't have bombed the Japanese. The result is that the student comes away with an overbearing image of American racism, sexism, injustice, etc., instead of what actually happened in the war. If you said "Guadalcanal" to anyone in my US History class in high school, they would raise an eyebrow. Say "Korematsu v. United States" and they'll be damned to let you forget it. I'm center-left in my political identity, but I totally understand when people say that public schools have a liberal bias. Usually, it isn't that they are explicitly propagating (they did in my school, but I grew up in the People's Republic of NYC) a liberal agenda and telling students what they should believe, it is that what they choose to emphasis and what they choose to omit from their teachings lead people to adapt a liberal stance on everything.