My sense is that in the following months of campaigning, voters were often frustrated by their inability to discover the real person behind the notably buttoned-up candidate.
What hurts so much about this sentence? First of all, voters shouldn't be at all interested in "the real person", if by that Broder means what kind of individual Hillary Clinton is - does she laugh at fart jokes, or make a good spaghetti sauce, or prefer smooth jazz to classic rock. Second, if these were important issues, it might have been the duty of Broder and his fellow journalists to kind of, you know, find out and let people know.
To many Washington insiders, for some reason known only to their therapists, Hillary Clinton is this big mystery. The fact that she is this big political ink blot to so many shows the problem with who Clinton is might not be Clinton's problem, but their problem. It might be the problem isn't that voters don't know who she is - I find it surprising that, having been in the national public eye for sixteen years, Broder could actually write that sentence so fecklessly - but that the Washington-based press corps hate her so much they refuse to write stories about her without looking through all sorts of lenses that distort whatever picture they might actually be getting.
Next Sunday, I'll really try something else that doesn't hurt so much.