It’s more accurate to say that living in a non-swing state is throwing your vote away than it is to say voting third party is.
Thomas W. Hazlett writes in the December issue of Reason:
I recently had a pleasant encounter with a great and outspoken American who, despite his libertarian leanings, supports Hillary Clinton for president. I congratulated him on making a tough call but allowed as how I was looking forward to casting my ballot for the Libertarian Party’s flag bearers, Gary Johnson and William Weld. “It will be unadulterated pleasure,” I offered, “as there is no opportunity cost.”
My correspondent fired back: “Opportunity cost is Trump gets elected.”
I stand by my recklessness.
Here’s where the curious nature of the American Electoral College comes in handy. Even where my vote—or the votes of my 100 closest, most easily influenced “inner circle”—might swing an election, there is simply no real chance that pushing either Donald Trump or Hillary Clinton over the top in South Carolina, where I live, will determine the outcome of the presidential race. If Hillary wobbles to victory in my current state of residence, she would have already demolished The Donald in the Electoral College. Similarly, in Maryland (where our family lived until 2014), a squeaker for Mr. Trump would indicate that Ms. Clinton had been vanquished in a yuuuuuge landslide elsewhere.