In his era, Johnson was rightly vilified in his escalation of the Vietnam War, but in other areas of legislation (the Civil Rights Act, Medicare, Medicaid, the anti-poverty Great Society) LBJ sought to uplift the underclass in this country, based on an empathy that is smartly expressed in the film. The assassination of JFK was a shocking act, and it was Johnson in the aftermath who had to reset the path of a nation.
Source: ‘LBJ’ is Important American History Brought to Light