I'm pretty sure we can separate the kiddy-diddlers from the standard corrupt politicians without being hypocrites.
Yes, and one of the differences is that Henry Clay being a slaveholder (which I think is the comparison being made?) wasn't universally seen as bad back when he was Speaker. It was bad, but the social morality of his day was conflicted on it. Plus, his attempts to save the Union were at least worthy of respect. But in 2015, I think everyone is united in saying that Hastert is a pedophile and that being a pedophile is wrong.