The debate also considers (in greater depth) a weaker claim: "If you favor higher taxes on a class of people that includes yourself, you have a greater moral obligation to voluntarily pay (part of) such taxes regardless of whether they are enacted."
Bryan Caplan, Tyler Cowen, and Bob Murphy, all libertarians, weigh in and agree with that weaker claim. (They are listed in approximate decreasing order of confidence in the claim.) Karl Smith, one of those who does want higher taxes, disagrees.
My take is that, despite superficial dissimilarities, the question reduces to that of unilateral disarmament (UD). That is, if everyone (else) would be better of for each person who (metaphorically) disarms, but you would be much worse off if only you disarmed, should you disarm? I say that, you do not have such an obligation, either morally, or for logical consistency, though it would certainly be a noble act. So, I think Karl Smith is basically right (about the implied obligation -- obviously, not about taxes!).
Just as in UD/public goods/free rider cases, the decision to UD will, for lack of a better term, "weed out the meme pool" of people like you, effectively rewarding those who favor opposite policies (which you, by stipulation, regard as pernicious).
It is for the same reason that you should not pay Coasean extortioners: though ostensibly, it works toward your goals, it undermines them by rewarding the wrong people.
I think Douglas Hofstadter made the point very well in his Tale of Happiton, which discusses this dynamic, but in the (less relevant, IMHO) context of nuclear disarmament. He's set up a public goods type situation in which "writing postcards" (i.e. to advocate nuclear disarmament) benefits everyone, but has its costs paid purely by whoever writes them. Watch how he subtly describes the dynamics of what happens when one person takes it upon himself or herself to do the postcard writing. (Here, it's a girl named Andrea.)
Andrea’s older sister’s boyfriend, Wayne, was a star halfback at Happiton High. One evening he was over and teased Andrea about her postcards. She asked him, “Why don’t you write any, Wayne?”.
“I’m out lifeguardin’ every day, and the rest of the time I got scrimmages – for the fall season.”
“But you could take some time out - just 15 minutes a day - and write a few postcards!” she argued. He just laughed and looked a little fidgety. “I don’t know, Andrea”, he said. “Anyway, me ‘n Ellen have got better things to do-huh, Ellen?” Ellen giggled and blushed a little. Then they ran out of the house and jumped into Wayne’s sports car to go bowling at the Happi-Bowl.
Naturally, Hofstadter wrote this piece to encourage people to UD ("write postcards") in such a situation. But I think he's just as well shown that, in the absence of a collective agreement, your decision to unilaterally disarm is, well, spitting in the wind.
(A version of this post was made as a comment on Bob Murphy's blog.)