Constructively critical and inclusive dialogue about conflictual issues is one necessary ingredient of both democratic citizenship and peacebuilding learning. However, in North American classrooms populated by heterogeneous and non-affluent students, pedagogies involving discussion of conflicts are rarely fully implemented, sustained, or inclusive of all students' voices. This article reports the results of a study describing contrasting ways in which teachers actually did implement (or attempt) dialogic pedagogies on difficult issues in Canadian public school classrooms. Based on a series of observations and interviews in 11 public elementary, intermediate, and secondary classrooms (linked to three different professional development initiatives), the article examines key elements--in the content of the conflicts discussed; in the processes and task structures for classroom discussion; in the norms, skills, and relationships established; and in the school contexts--that make such dialogic classroom activities more (or less) feasible to implement and sustain, more (or less) inclusive of previously marginalized voices, and more (or less) constructive for democratic and peacebuilding education.