The best thing a voter of any persuasion could do at this point is vote for an independent, or even better, third party candidate.
The reason is this, almost everyone would agree that the political situation in Washington is severely flawed. Even though we have alternative candidates run in presidential elections they are usually viewed by a large portion of the electorate as spoilers. This happens when the alternatives are either conservative, Perot or Wallace, or liberal, Anderson or Nader. The electorate gets sold on the idea of voting for a winner. The problem that occurs then is that the winner has put together a large enough "tent" that those who came along to just get someone who may do something some things they like get both minimized and taken for granted.
Let's suppose that the electorate were brave enough to encourage candidates of both political persuasions to run. It is very possible you could even have a candidate elected to the oval office with a popular vote in the low 30%s. In such a case the elected person would be so weak that they would have to continue to court voters who voted for someone else just to maintain any sort of power. Those voters would have much more influence, even though they voted for someone who lost the election.
Even if only one alternative candidate runs and has a strong showing they can influence the policies of the other parties, some have suggested that the fiscal responsibility of the 1990's waspartly due to the strength of Ross Perot's campaigns.
Democracy is under threat in the United States, from special interests, from the pollution of excess campaign contributions, and from the disaffection fringe voters feel from being marginalized by the process. Having multiple candidates vying for office may make the system messier, and more chaotic, but it would also pull more people into the process making them feel less like giving up, or worse, becoming radicalized.
So do the country a favor. Vote for someone who actually stands for what you believe in.