I'm tired and bitter, but: there's no rule saying good outcomes are possible.

It's entirely possible to say "this is a false dichotomy, both parties are fundamentally hopeless on this issue" and also say "third party candidates are completely unelectable".

I'm not entirely fatalistic; I think "a major party greatly realigns its views on privacy" is possible, if hard and unlikely. I mentioned Rand Paul and Bernie Sanders as contrarian voices each pulling their party away from bulk surveillance, and I hope we'll see more such voices in the future. A realignment looks increasingly possible, and increasingly necessary. But I honestly don't think "third parties are powerless" should be seen as a reason to have any hope at all for our existing options.

Why does that matter? There's a lot of distrust for both parties, from both sides at the moment. That seems like a good time for a 3rd party to come on in.