I likely include both Truman and Nixon out of habit, though they were the "book-end" presidencies.

MLK did put on the pressure that resulted in Ike's 6-23-58 meeting with Civil Rights leaders. Martin was 29 years old at that time, and while he was gaining national influence, the President was more interested in the other older, more established leaders of the movement. To be fair, Ike was sincere in his belief that their approach was more beneficial to progress in "race relations," than the young, more confrontational minister's.

Ike's VP actually had a much closer relationship with King. Indeed, Nixon lobbied for Ike to meet with King. Yet, as history shows, the cautious President would do so in a group setting -- distinct from Nixon's personal relationship with King. (It's interesting to speculate on what might have happened if Nixon had, during the 1960 election contest, reached out to King's people, in the manner that JFK did to Mrs. King? Until that point, both Rev. Kings -- Senior and Junior -- were registered republicans. Those southern black citizens who did vote tended to support republican candidates. When the Kings came out for JFK, it changed that dynamic.)

Now, let's fast-forward to April '67, at the time when King delivered his most prophetic message to America. He publicly opposed the war in Vietnam, thus breaking the increasingly strained relationship with LBJ. By identifying those "giant triplets" of militarism, materialism, and racism, King was challenging a heck of a lot more than LBJ's policies on Vietnam -- and the speech could not be mistaken as an endorsement of Johnson's damaged Great Society as such.

King was being pressured to actually run on a presidential ticket with the nation's top "baby doctor." He knew that Nixon was running, on a vague promise to bring peace with honor in Vietnam, and lawn and order to America's cities. Nixon, that snake, would hint that the Great Society programs promoted lawlessness, even riots. This was part of his "southern strategy," to compensate for the loss of the black voters' support.

Hence, a small group -- led by a retired general and a former senator -- pretending to be an independent-from-the-White House organization (but directed by LBJ), came out loudly in support of LBJ's policies in Vietnam. They identified themselves as the "anti-anti-war" advocates. One of their best-known spokesmen was, of course, Harry Truman. Though Harry wasn't about to mention him by name, he was outraged by King's attempts to combine the Civil Rights and anti-war movements. He could not be objective, for he had a major share of the responsibility for the US involvement there.