A perfect response

You've all probably heard the argument that voting in democratic elections is irrational if your only goal is to influence policy through participating in a choice of candidate(s): the ex ante probability that your vote will actually matter at the margin is so incredibly low that even if the opportunity cost of casting a vote isn't very high, it still by far outweighs expected benefit. (This isn't the same as saying that voting is irrational in any absolute sense, just that when people vote, they aren't motivated by policy only. In some ways, the very act of voting must be enjoyable to people.)

Now if you use this argument to show someone who is deeply convinced that their only reason for voting is influencing policy that this conviction must on some level be wrong, their standard counterargument is a variant of "What if everyone thought this way?" It's not a valid counterargument, to be sure, because it doesn't even address the point, but I have to admit I usually had trouble explaining exactly why it's not valid.

Well, thanks to the editor of Economic Enquiry R. Preston McAffee, we now have a perfect retort to this counterargument. Sure, McAffee's response was fashioned to argue a different point, but it's general enough to apply here and in many other like situations:

It is like saying that Taco Bell should not exist because it would be a bad thing if Taco Bell were the only restaurant in the world.

(HT: EconLog.)