Leaked emails are another matter. But to compare hacking with leaking is self-serving. Leaking is where one party who was a valid and legal recipient, gives out the data. Hacking is illegal access bypassing what prevents anyone but the legitimate owner accessing it.
Ask yourself: are you politically active, even on a blog or forum? Are you okay with any of the people who post to the blog or forum and agree with you getting hacked, because it's politically expedient? If you say that it is okay to hack someone on the right's email, then when it happens to someone on the left, you won't complain? It'll be just as valid in your eyes, right?