Abraham Lincoln became president during a time of need in America. The states were divided North and South and had no intentions of changing that and even went to war because of the divisions. Lincoln was responsible for the abolition of slavery and passing the 13th-15th amendments (abolishing slavery, allowing for education of African-Americans, and allowing them to vote). The mere thought of equality was absurd to them and the fact that Lincoln was doing everything he could to obtain equality was the "fault" that got him killed. The search for faults in President Lincoln hurt America because it happened right after he was elected for a second term where he could have done a lot more in obtaining equality between blacks and whites.
Martin Luther King Jr. may not have been a president but he was an American leader. He lead the Civil Rights movement and gave the famous "I have a dream" speech. MLK wanted equality and peace just like Lincoln did and was assassinated for the same reason. Even before his assassination, he was beaten and jailed because of his actions of seeking equality. If the assassination hadn't happened then maybe there would be less issues today within the topic of race. All MLK wanted was equality and in a way he got it because there is no more segregation. If he did not die so early within the movement then maybe there would be less turmoil among the different races. The "fault" that killed MLK was his relentless search for equality.
Leaders are the face of whatever it is they are leading. Presidents are the face of America and MLK was the face of the Civil Rights Movement. It is precisely that reason that begins the search for the leader's faults. Not everybody agrees on everything and the difference in opinions is the fire for the "fault search" and the difference in opinions is what got Lincoln and MLK killed. People didn't agree with what they fought for (equality) and killed them because of the progress they had. As long as people disagree there will be a search for the leader's faults in order to stop what they are fighting for.
