That's the question that's posed by Alex Tabarrok at Marginal Revolution; his answer is, in a sense, almost certainly yes. His reasoning goes as follows:
Did Mitt Romney ever speak with Angela Merkel, whose phone the NSA bugged, or any one of the dozens of her advisers that the NSA was also bugging? Did Romney exchange emails with Mexican President Felipe Calderon? Were any of Romney’s emails, photos, texts or other metadata hoovered up by the NSA’s break-in to the Google and Yahoo communications links? Almost certainly the answer is yes.
Did the NSA use the information they gathered on Mitt Romney and other political candidates for political purposes? Probably not. Will the next president or the one after that be so virtuous so as to not use this kind of power? I have grave doubts. Men are not angels.
The entire entry is not terrible long and well worth reading.
Related: An interesting article on why email encryption is so little used. The piece, by a computer science professor named Matthew Green, asserts, "More than ninety-five per cent of all e-mail flowing over the Internet today does so in a vulnerable, unencrypted form." If my own experience is any guide (perhaps it isn't, but I know many libertarians), the correct figure is closer to more than 99 percent. Green explains why the Dark Mail Alliance has the potential to make encryption more common.
There's also an interesting email initiative in Iceland called Mailpile. Disappointingly, Green doesn't weigh in; I would have liked seeing what he thinks of that effort.