... The most important missed opportunity was the chance to study how the president of the United States came to work closely with a grassroots movement deemed radical by much of the nation. Presidents and social movements often find themselves at odds; presidents tend to distance themselves from the activists deemed essential to campaigns but politically problematic to governing. This was the case with President George W. Bush and the Religious Right, as well as between President Obama and environmental activists.

But from January to March of 1965, intense communication and coordination emerged between President Johnson and the leaders of the civil rights movement. During the phone conversation between Johnson and King recorded on January 15, 1965, the two men can be heard thinking through common objectives and strategies to achieve them. Both men are trying to figure out how to get the Voting Rights Act through Congress. Johnson believed that civil rights activists could help apply pressure on Congress to pass his bill, while King sounds confident that he is talking to a president who would move forward with the legislation at the right moment.

A second missed opportunity was the possibility of providing a more accurate understanding of the immense opposition that civil rights advocates faced. To be sure, the movie captures the ferocity with which southern white citizens, local police forces (led by Sherriff Clark), and Governor George Wallace stood firm—and used violence—against the protesters. But it downplays the enormous obstacles that civil rights advocates confronted within Washington’s political establishment when they pushed for the Civil Rights Act in 1964 and the Voting Rights Act in 1965. Popular and scholarly accounts of the civil rights struggle don’t take Congress sufficiently into account. Many congressional leaders operating at the center of power within the institution didn’t want this bill. Between the late 1930s and the early 1960s, a coalition of Republicans and southern, conservative Democrats had dominated the legislative process and blocked progress on liberal legislation. After their stranglehold on Congress was broken by the election of 1964, liberal legislators commanded huge majorities in the House and Senate.

But Johnson had watched powerful conservatives for too many years and feared that sending a second race relations bill too soon could cause a backlash from moderate Democrats and Republicans wanting to move on issues like health care and education, endangering his broader agenda as well as voting rights. Congress is the elephant in the screening room: without understanding its power structure, viewers cannot understand the political concerns expressed by Johnson in his debate with King over the bill’s timing. ...