good evening, and welcome to "politics nation," tonight's lead, a struggle continues. and therein lies the point, because right now, as i have for the last few years, i struggle with dislocation and even i admit, disbelief, that our nation, that as the nation prepares to honor, possibly, its most transformative leader tomorrow, so many of the defining and uniquely american battles that marked and marred the life of reverend dr. luther king, either remain or have evolved into even greater social institutional and, now, national security threats. it also appears too many americans are deliberately