MLK was offered the VP spot in RFK's run for president and both of them got whacked. Common denominator = pulling out of the Vietnam occupation.
Things look similar today.
""It remains a point of controversy among historians whether or not Vietnam would have escalated to the point it did had Kennedy served out his full term and possibly been re-elected in 1964.<24> Fueling this speculation are statements made by Kennedy's and Johnson's Secretary of Defense Robert McNamara that Kennedy was strongly considering pulling out of Vietnam after the 1964 election. In the film "The Fog of War", not only does McNamara say this, but a tape recording of Lyndon Johnson confirms that Kennedy was planning to withdraw from Vietnam, a position Johnson states he disapproved of.<25> Additional evidence is Kennedy's National Security Action Memorandum (NSAM) #263 on October 11, 1963 that gave the order for withdrawal of 1,000 military personnel by the end of 1963. Nevertheless, given the stated reason for the overthrow of the Diem government, such action would have been a dramatic policy reversal, but Kennedy was generally moving in a less hawkish direction in the Cold War since his acclaimed speech about World Peace at American University the previous June 10, 1963.
After Kennedy's assassination, new President Lyndon B. Johnson immediately reversed his predecessor's order to withdraw 1,000 military personnel by the end of 1963 with his own NSAM #273 on November 26, 1963." -- from
http://en.wikipedia.org/wiki/John_F._Kennedy