... The question facing voters is whether to oust a polarizing school board that has championed charter schools, performance-based teacher pay and other education measures supported by conservatives. 

But the vote here in Jefferson County, just west of Denver, has become a money-soaked proxy war between union supporters and conservative groups like the Koch-backed Americans for Prosperity, testing whether parents in an election-year battleground believe a rightward turn in their schools has gone too far.

... “I can take it,” said Julie Williams, one of the three conservatives, who said she had received harassing emails. “For my kids, it’s been pretty hard. I come from a strong family. We believe in standing on principle, even with malicious attacks on me personally. ” 

In September of last year, thousands of students walked out of school when Ms. Williams proposed shifting the focus of the Advanced Placement United States history course toward patriotism and away from “civil disorder” and “social strife.” It was a moment when festering disputes among parents, students, teachers and the board leapt into the national news. Even though the curriculum was never changed, many voters around the district say they are still upset. 

“When you have high school kids having walkouts trying to get an education, it’s astonishing,” said Randy Kubes, who answered Ms. Gurdikian’s knock. He said he was planning to vote against the conservative majority, adding, “Those people are taking us back to the Dark Ages.”