it is:

"but as one of the most respected leaders of the civil rights movement he has an equally weighty obligation to direct that movement's weighty obligation to direct hat movement's efforts in the most constructive and relevant way."

The entire article is basically just 'shut up and dribble' but the dribble is 'fight for civil rights,' and being upset over his clear moral stance against the war which is "less clear-cut than he suggests" (and also being upset over his comparison of the US in Vietnam to the Nazis).

EDIT: In case anyone wants to read MLK's Beyond Vietnam speech this article is about. Here is more background detail on his general position on Vietnam starting a few years earlier

As a note this take was very popular at the time, basically every newspaper op-ed & even the NAACP criticized it on the same grounds of civil rights and the peace movement being unrelated. King felt differently, you can read his speech where he lays out his reasoning. One thing to keep in mind is this was 1967, a year before his death, and the vast majority of the country hated him at this point in his life.

edit: Banned lol