Not surprisingly, the bulk of part two was the Vietnam War. This seemingly minor war became like an avalanche--building and becoming more involved and bloody as the years passed. And, combined with anger erupting from years of racism, society began to crumble. Protests and violence became commonplace and Johnson seemed ill-prepared to respond. In fact, it would seem that the documentary establishes that Johnson's strong personality, for once, made things worse. He could not bully his way into positive change and he seemed unwilling to listen to dissent.
Overall, I think this second episode is actually better than the first. It's more complete and narrow in focus. In other words, part one crammed over fifty years into the same slot as part two which covered only a decade--allowing for a greater analysis and insights. Fascinating and complete.
By the way--just a bit of warning. The images of death in Vietnam are pretty intense. Think twice before you have kids watch.