I don't think it is badly written, he bandies about SAT words and uses them correctly. Trickily, he applauds the work of what were basically Soviet front groups, but still maintains a journalistic distance. Since we know nothing of what Obama was doing at the time, it is easy to imagine him having recourse to doting editorial assistance.
As you might know, studies comparing the writing style in O's "autobiography" "Dreams" with that in known Ayers works suggest strongly that Ayers was the real author of that book allegedly written by Obama. Combine that with the facts that Ayers was geographically proximal to Obama at the time the latter was at Columbia and that Ayers would pretty much agree with the content of the Sundial article, and you can see why Ayers would be a suspect in such "editorial assistance."