Is there a historical pattern in America where it's visionary leaders are routinely culled?

Take for example Abraham Lincoln who stood for a united America, those who opposed his idea's, well you know what they did....then fast forward about one hundred years, what do we get, yet another visionary, JFK, do I need to say more. His brother in an attempt to propagate his legacy decided to run for the U.S presidency then, oh nooooo! This phenomenon is not limited to America, Mahatma Gandhi in India, introduced some rather radical ways to bring about change or freedom, that were adapted by Martin Luther King. These people represent the pillars of modern social engineering whose ideas have way outlived them and we have come to embrace them as modern day prophets. MLK in one of his speeches talked about not getting to the “promised land”, a self inflicted prophecy that tragically came to p. Barrack Obama, has in one of his campaign speeches said that he would like to have a running mate who would “take care of things”, should anything happen to him. This is eerie.