I think a narrator to tie together the news reporting and the expert testimonial (and maybe a 2nd expert, too) would have helped because then those opening title introductions could have been cut, and it would have made the whole thing more entertaining.
The whole key-lime pie bit was fun, I liked that a lot!
I think it would make your point stronger if you had made them menacing looking, for the most part they were pretty innocent looking (unless you're afraid of clowns), but if they were to look mean or scarier then you're point about "racism and human mentality," as kinglis put it, would have been stronger.
Finally, I really liked the feel you gave it that the video is about 10 years past the incident, and the government has released a sort of information/educational documentary about Klowntown, that was done well, and that last scene where you cut from reporter to reporter was good, but if you would have done the cuts faster and each clip shorter, I think it would have made it feel more like an ending, I was ready for one more scene after that...I dunno, just my thoughts.
Very good though, good quality, nicely edited, good work, man!