Ultimately the election comes down to which vision for America are you going to support. The vision that is for liberty, individual rights, independence, a market economy and all of its attendant risks and downsides or the vision that favors collectivism, group rights, dependence, statism and all of its attendant risks and downsides. One side understands that everything can't be perfect but given the trade-offs, we do the best we can. The other side seeks to undo every aspect of the pain, struggle and inequities of life on their march toward Utopianism.
If you vote for Ron Paul, you may feel pure and be able to morally preen in front of your fellow man, but you will be wasting your vote. A vote for him, although cathartic, may reveal a lack of understanding of our political system or an I-don't-give-a-damn attitude. We are not Britain or some other parliamentary system where coalitions are built after the election. In America the coalitions are built prior to the election which coalesce as the two-party system. You must vote with the system we have not the one you wish we had. (A valid retort is: "If you don't vote for Ron Paul, it may reveal that you have given up on correcting the slide away from Americanism.")
Come to a decision about which movement better represents your notion of the correct way to run a government.
If you think that the primary function of the government is to act as the social welfare agent that reduces virtually all risk and mandates that the country should operate largely as a collective commune by running our schools, healthcare, retirement and virtually everything else, then you have a choice.
If you think government should provide national protection, preserve individual liberty and protect private property, you have a choice.
If you think that the government should create a hostile business climate that drives jobs and business overseas forcing more layoffs here at home, then you have a choice.
If you think a government should have limited powers, duties and responsibilities and think that government is best when it governs least, then you have a choice.
If you think government should make decisions based on a grievance culture that is always angry and must constantly agitate race, gender and class issues to maintain power, you have a choice.
If you ascribe to the idea that everyone should be free to pursue their happiness, you have a choice.
Utopians and fundamentalists flagellate and complain that none of the candidates suits their purpose. Well, the only candidate or party that you will fully agree with on every issue is candidate 'you' and the party you head. Otherwise, life is full of compromises and voting is just one such compromise. Believers in an afterlife can put off Utopia for another time. Athiests are just stuck with sucking it up and realizing that Marx was right that human nature would have to change radically in order for us to enter the land of milk and honey any time soon. And 3000+ years of documentation of human activity suggests there isn't a lot of evidence that human nature is making any sweeping changes.
But there are clear differences between the two parties in America. And neither is perfect. If you want perfect, go to church. But candidate Obama was very clear that he was none too happy with Americanism and wanted to make fundamental changes to the fabric of America.
So go ahead, cast your vote.