Stephen Wolfe has an excellent piece at Mere Orthodoxy on the consequentialist theory of voting. He challenges the assumption that voting for a candidate is an endorsement of their moral life, and that it is necessarily hypocritical to tolerate immorality for a candidate in a given situation, but not another. His demonstration that the assumption of endorsement is misplaced is strong, but ultimately fails to convince in his conclusion. His principle is,

Voting for a candidate is an endorsement of the candidate’s moral life as it pertains to his external conformity to civil righteousness sufficient to qualify the candidate for civil office, qualifications judged by the likely preponderance of good or bad in the long-term consequences of his term in office determined by his political actions after mediated through the institutional constraints of his office and the checks and balances of other institutions.

The candidate’s ability to enact policies, the details of those policies, and the bearing of the candidate’s morality on those policy enactments are the only endorsement of the candidate’s moral life made by voting. Wolfe in his conclusion states, “And as I argued above, a moral standard as a first condition for vote-worthiness is arbitrary, unless it is shown to be relevant to good civil outcomes resulting from civil actions in a particular time, place, and set of circumstances mediated through particular political institutions…”