A shame that you did not name Smedley Butler, nor expand upon his relevance to this situation.
A man of unquestionable honor and valor who served his nation in all that it asked of him - he also blew the whistle on the (likely hare-brained) "business plot" to replace a democratically elected administration that threatened big business interests. The result was that the (big business owned) newspaper chains ridiculed what he had to say, even though Congressional investigation found there was substance to it. But of course no action was taken against the conspirators.
"Going to the press" would have served Snowden no better. No American media outlet would have touched his revelations, and in this case the perpetrators were the government itself.