The Generalization Argument: You're obligated to vote because it would be a disaster if no one voted.
Loren Lomasky and Geoffrey Brennan provide a convincing reply to this argument. In brief, it proves too much. It would be a disaster if no one fixed cars, but you're not obligated to become a mechanic. It would be a disaster if no one dispensed prescription drugs, but you're not obligated to become a pharmacist. And so on. They suggest a stronger version of the argument is as follows: "Strictly speaking, what makes an ungeneralizable action wrong is not that it fails the generalization test. Rather, it fails the generalization test because of underlying unfairness, and it is the unfairness that accounts for the action’s wrongness.” The mere fact that it would be bad if no one voted isn't what makes it wrong to not vote; rather, it's wrong not to vote because you wouldn't be doing your fair share. This brings us to the second argument:
The Fairness Argument: You're obligated to vote to meet your duty to contribute to the common good and a just society.
Jason objects to this argument, rightly to my mind, via an appeal to what he calls the particularity problem. It's true we have a duty to not free ride on the contributions of others, but we can do our fair share in ways that do not involve voting in particular. Our contributions can take a variety of forms, including donations, volunteering, and more. Indeed, I might take this argument a step further and say that it's better to make non-political contributions. As I put it in my book:
Suppose we’re on a camping trip where everyone has plenty of water to drink. I’m debating what kind of contribution to offer. I can make a costly-but-needless trip to the well or I can do something else that satisfies an unmet need, like gather firewood. At a minimum, it’s permissible to not fetch water and gather firewood instead. Gathering firewood is a perfectly fine contribution to the trip; I am not guilty of “free riding” on the work of the campers who collected water simply because my contribution takes a different form. Indeed, it seems to me clearly preferable to gather firewood. Given that sufficient water has been collected, getting more water doesn’t do any good. So doing something else with my time, like gathering the firewood, makes a more valuable contribution. The same point applies to political abstention. Political activity is no different from other occupations such as delivering the mail: just as it would be inefficient for everyone to deliver the mail, it is inefficient for everyone to be politically active.
The Collective Samaritanism Argument: This argument comes from Julia Maskivker's outstanding book The Duty to Vote, which provides the strongest and most comprehensive defense of a duty to vote in the literature. We have a duty to contribute to highly beneficial collective activities when we can do so at a low cost to ourselves—even when your individual contribution is inconsequential. To adapt a case from the book, if we see a car in the middle of the road, we have a duty to help others push it to safety even if our individual contribution won’t make a difference to whether the car is moved successfully. Similarly, voting well is a highly beneficial collective activity that promotes justice and social welfare and so we have a duty to contribute our good vote given that we can do so at a low cost to ourselves.
However, I believe that an individual may do their Samaritan duty without voting, by promoting justice and social welfare in other ways. To elaborate on the car example, suppose you see that sufficiently many people are pushing the car to safety such that your help won’t make any difference. You also notice that a car accident victim is at the side of the road in need of CPR, which you are able to perform. Here you can do your Samaritan duty by tending to the particular person and allowing others to push the car out of the road. Indeed, the very consideration that speaks in favor of joining the car pushing effort—concern for the welfare of people on the road—speaks at least as loudly in favor of performing CPR. (We could even describe both forms of help as part of the same collective effort to ensure the safety of those on the road.)
Similarly, suppose you know that sufficiently many people are voting such that your vote won’t make a difference. You also know that the effort you could allocate to preparing and casting a good vote could be spent earning income to donate to an effective charity. Here you can do your Samaritan duty by donating rather than voting. Indeed, as in the car case, the very consideration that speaks in favor of voting—promoting social welfare and justice—speaks at least as loudly in favor of charitable contributions that make more of an impact on people's lives.