It makes sense that this really smart CNN documentary series would be perceptive enough to single out the year 1968 as one volatile and meaningful enough to warrant its own hour – titled, simply, 1968. And what relevance does that year hold today? Well, start with the Soviet incursion into Czechoslovakia, if you want modern parallels. And if you want pivotal historical events, start with the assassinations of Robert F. Kennedy and Martin Luther King, Jr., and the election of Richard Nixon, and… well, watch and see. It’s amazing, and frightening, that all of that happened in one explosive 12-month period.