 CORE represented a major bloc of dissent at the 2012 AFT convention, and held signs in protest of Race to the Top during a speech from Vice President Joe Biden.In spring of 2018, the Chicago Teachers Union and Chicago Association of Charter Teachers and Staff Local 4343 voted to merge, with the charter educators forming a new division within the CTU.On December 4, 2018, CTU members at the Acero charter school network initiated the first strike at a unionized charter school in US history.