Michael Ratner, one of America’s great human rights crusaders and constitutional lawyers whose lifetime of activism began in 1960s protests, died Wednesday of complications from cancer. He was 72. Ratner’s work spanned five decades and more than a dozen countries. He led the New York City-based Center for Constitutional Rights, one of the nation’s bulwarks for protecting the rights of activists, protesters and whistleblowers. His most recent legal fights included his work to protect WikiLeaks founder Julian Assange from prosecution in London, a 13-year battle through CCR to shut down Guantanamo, and an aggressive campaign to stop the Obama administration's use of drone warfare and the extrajudicial murder of U.S. citizens abroad.