IMO, American journalists are cribbing from
The Economist. See page 200 of the search results available
here. On that page and the ones preceding it, one will see articles on the McCain insurgency during the 2000 primary season. On page 157, one will find an article on Dean's insurgency against the Democratic Party's establishment leading up to the 2004 primary season.
Does the word, given the times, have a double meaning? Yes, but what words don't? Does this usage undermine "insurgents" political legitimacy? Or do we do that ourselves when we parse the words and expressions the other guys use--without doing the same with our own?