> It makes me wonder if the government embraces, and perhaps even plants, ideas like this.
With full awareness that governments have done this, I really wish people would stop thinking that if a group of rational people oppose things done by one of our heroes, that it could only be as a result of a government sockpuppet.
Rhetoric as a concept or tool is incredibly expansive, it's hardly limited to just government. And it wasn't that long ago that Che Guevara was insulting the USA during his speech to the UN for the Ku Klux Klan, the existence of which should readily demonstrate that the people themselves will erect biases and grudges of their own independent of (and often contrary to) government interference.
The same government responsible for the agency that threatened MLK, also had to forcibly integrate segregated schools, and forcibly adopt so many other civil rights measures that are still debated today.
But in any event if you have paid enough attention to politics (or at least American politics) it would be clear that having minor scandals is not only not a roadblock, but can often be used to great effect in a politician's career. If one thinks "the people" are too stupid to figure this out then would could possibly be the point of a democracy?
Let people point out what they want about Dr. King, Nelson Mandela, or anyone else (especially if it's true!). People see the world through different lenses, one may worry more about what our hero does "when no one is watching for compliance" as a measure of integrity. Another may worry only about what the hero does in public as a measure of effectiveness. That doesn't make one or the other of these people a government plant, it just means that we're (wonderfully) different.