Privileges Within Privileges Within Privileges...
Update: See also a defense by noted conservative reactionary and puppy smasher Henry over at Crooked Timber.
I can see where TBogg is coming from. It is certainly the case that an Obama presidency would be objectively better for the vast majority of Americans than a Romney presidency. So there is a degree of truth to the argument that someone who would vote for Gary Johnson rather than Obama, and thus increase the likelihood of a Romney victory, may be arguing from a position of privilege1.
However, I can make the same argument in support of Gary Johnson. Rephrasing Erik Loomis: Given that Obama voters probably don't have to worry much about being blown up by drones it's a luxury for them to be concerned with labor, abortion rights, gay rights, environmental policy, etc., etc.
This is a hard problem. Fridersdorf is more privileged than the typical Obama supporter who is, in turn, more privileged than some person in Pakistan who lives in real danger of being caught in a drone attack2. Given this ladder of inequality for whom are we to vote?
One answer is that voters need only concern themselves with the effects of their choices on other Americans, which may be supportable from a pure procedural standpoint, but generally seems morally myopic. However, if we admit that voters should care about individuals outside of America then the question becomes (something along the lines of) "Whose presidency would best benefit humanity?". In that case Gary Johnson might be the right answer, given the amount of havoc that American military and drug policy, fully supported by Obama, has wreaked on people around the globe.
Like I said, it's a harder problem than it seems at first glance. Fridersdorf may simply be arguing for the right thing for the wrong reasons.
1 Though the issue is a lot more complicated than that, see Brennan on compromise voting.
2 Who is, in turn, probably more privileged than a whole host of people in sub-Saharan Africa.