AKMA points out a brief essay by Alisdair MacIntyre entitled The Only Vote Worth Casting in November. In it, MacInytre suggests that the only ethical response to this election is to reject both candidates. Here's the introductory paragraph:

When offered a choice between two politically intolerable alternatives, it is important to choose neither. And when that choice is presented in rival arguments and debates that exclude from public consideration any other set of possibilities, it becomes a duty to withdraw from those arguments and debates, so as to resist the imposition of this false choice by those who have arrogated to themselves the power of framing the alternatives. These are propositions which in the abstract may seem to invite easy agreement. But, when they find application to the coming presidential election, they are likely to be rejected out of hand. For it has become an ingrained piece of received wisdom that voting is one mark of a good citizen, not voting a sign of irresponsibility. But the only vote worth casting in November is a vote that no one will be able to cast, a vote against a system that presents one with a choice between Bush's conservatism and Kerry's liberalism, those two partners in ideological debate, both of whom need the other as a target.

Needless to say I've ignored his advice, and feel very ethical for having done so. But it's still an interesting opinion, and he makes some solid points about the nation's responsibility to families. I forwarded the link to my Ethics professor.