In 2006, I left the largest high school in Chicago — Lane Tech, a selective enrollment high school with a diverse student body — for another selective enrollment school, King, with a predominantly African-American population.

Still a high school chemistry teacher, my work at Lane as a delegate to the Chicago Teachers Union’s governing body, the House of Delegates, brought me into deep conflict with the principal, who I felt was a bully, unethical, and hypocritical. While he was never able to retaliate against me, he went after my closest friends and colleagues. So I left.

When I got to King, the delegate (with whom I had served on the Executive Board) wanted some support; I, however, wanted to keep a low profile. But she had won election to the executive board of PACT (Pro-Active Caucus of Teachers and School Employees), a reform caucus that challenged the stranglehold the UPC (United Progressive Caucus) had on CTU leadership. I joined pact in 2001 — the same year the caucus won the election and took control of the union.