Claim: The lesser of two evils is still evil, and should not be legitimately supported.
If you disagree with the idea of voting on moral/legal/philosophical/rational grounds because you feel it is an illegitimate use of coercion (and thus worsens the human condition), you should not vote. Say some society has developed whose members believe, truly believe, that “adding various strains of cholera to the drinking water by voting” is the only way for its society to operate (much like Americas are apt to believe that “adding various representatives to the federal government by voting” is the only way to assure some kind of progress). Cholera A does this and Cholera B does that and so on and so forth. Some people may call for less cholera in the water, while others may plain a “cholera stimulus package” — you get the idea. Now suppose, someone who disagrees with the idea of adding cholera to the drinking water by voting on moral/legal/philosophical/rational grounds because they feel it worsens the human condition, they should not vote. Yes, Cholera A may be objectively better than Cholera B (just as Harry Reid may be better than Sharron Angle or vice versa), it does not, in any way, legitimize the use of cholera to better the human condition. Similarly, just because one candidate may be better than another, it does not, in any way, legitimize the use of a coercive government to better the human condition.