I find the repetition a little irritating too, but Carrol's not wrong, and your objection both misses his point, which is highly relevant, and indicates that maybe Carrol's right to repeat. The point isn't that both are bad, which they are, but that leftists are mistaken when they repeatedly think Democrats should be able to transcend the strictures of governing capitalist democracy and "do good." The whole idea of "hope" rests on the belief that Democrats _are able to_ -- which is a separate question from _having the will to_; this is the question Dennis Perrin and Richard Seymour, among others, are interested in -- enact the change that commies, anarchists, and others want. They aren't, and so Carrol's saying that it's silly to pretend they can. His insistence on this point isn't trying to discover The Truth; he's just addressing leftists.
(*Of course, hypercynicism about Obama and the Dems is, to use your analogy, just the flipside of hope.)