By TOM SHANAHAN Martin Luther King Jr. initially hesitated to accept an invitation to speak at Southern Methodist University in 1966, a time and place where resistance to integration persisted. The Civil Rights icon explained to an SMU student senate leader that the Dallas school had rescinded an invitation a couple years earlier. Bert Moore, who won election as student senate vice-president despite opposition campaign posters labeling him an “integrationist,” appealed to SMU president Willis Tate. Tate assured…