> surely Obama and friends couldn't deal with the outrage that would follow? Their image is already shot.
I can't figure out how this would actually matter to Obama, more than a few speeches' worth. Except for a few thousand libertarians, the people most upset by this were Obama's most fervent supporters, who won't be voting for him again anyway. The administration's main political foes seem to recognize that there's a big issue here (after all, slightly more than half of their constituents think that the NSA actions are "hurting Americans"[1]), but don't quite know how to capitalize on it, since they were all in favor of things like this before the story broke. The outrage within the US about this is spread so evenly across the usual parties that it's not clear that there will be any actual fallout for future elections.
> The death of Snowden would put them on par with mafia.
I would suppose that if they choose to kill him, they'll try pretty hard to do it in a way where it's not provable that the US killed him. Future-leaks-wise, though, it might seem beneficial for people to suspect that the US killed him, since presumably that would deter future leaks to some extent.
[1] http://www.foxnews.com/politics/2013/06/25/fox-news-poll-mix...