1) Postpone your calculated support for someone you don't like until you're standing in the election booth. Before then, support the third-party nominee you'd like to see win. If a pollster asks who you support give their name, not the major-party candidate you may wind up voting for in the end. Doing so doesn't squander your vote on someone who won't win, but could be the difference between a Libertarian or Green Party candidate being included or excluded from TV debates.Look, this is thinking about things completely backwards.
2) Think about whether or not you live in a swing state. If so, maybe it makes more sense to vote Republican or Democrat. But if you live in a state like California, where the Democrat will obviously win, or a state like Utah where the Republican is obviously going to win, your vote is going to have a lot more impact if you're part of a third-party surge that signals disaffection to others.
The truth is that Friedersdorf's target group here is actually pretty small. We're talking people who care enough about politics and public policy to have strong opinions, but whose opinions aren't close to being represented by the major parties (presumably we're only talking about people who have major across-the-board conflicts, not Republicans who want gun control or Democrats against marriage equality). And then on top of that, he's talking to people willing to act strategically. Put it all together, and it's a very small group.
But it's a group which is already, by definition, putting an enormous amount of time and energy into politics already, if only by reading (or viewing) a lot of it.
The deal is that if you're that kind of citizen, then you can, and perhaps should, be doing a whole lot more than just voting in November. At the very least, you should be voting in presidential primaries -- and your vote there (at least if you are lucky enough to live in the right state) is worth a whole lot more than your vote in November). But that's just the start of it. The truth is that American parties are permeable, and if you're the kind of citizen Friedersdorf is talking about you can have some real influence.
You can attend party meetings. You can volunteer with a campaign, especially a sub-presidential nomination campaign. You can talk to your friends and family. You can, of course, donate money. You can, if you have the skills, write about how your party should change to reflect your views. You can, if you have the skills, recruit people to join the party and help change the balance of power within that party.
Of course, all of that means you have to start by choosing a party, which means you'll be choosing a party with which you disagree on lots of things. That's the price for effectiveness.
There is another plausible path: get involved with an interest group. If you hate torture and detention policies, get involved with the ACLU or Amnesty or whoever is working on those issues.
The point is that if you care enough about all of this to think about it, you have resources -- at the very least, information -- that is at least somewhat useful politically, and at any rate more useful than your vote.
And you know what? If you want, if you're in this group and you've acted to move your party towards your views or to strengthen an interest group, and then you get to November and really just can't stomach voting for Mitt Romney or Barack Obama..hey, if you want to vote for the Greens or the Libertarians or whatever, knock yourself out. Your vote just doesn't count enough to make it a major political sin; it's more like a minor misdemeanor.