All my life, I’ve cast votes in presidential elections that were votes against the Democrat rather than for the Republican. Such is life. Sure, the Dole ’96 campaign had all the explosive excitement of road tripping to Dubuque in a Crown Victoria, but it wasn’t hard to vote for the guy, considering the alternative. Voting in American presidential politics usually requires discerning voters to resolve not to let the perfect be the enemy of the good enough.

This year, though, I’m close to being done with that compromise. At the risk of scandalizing my high school civics teacher, this might be the first presidential and congressional election I’ve sat out on principle. As a character in Richard Linklater’s film “Slacker” says, “Withdrawing in disgust is not the same as apathy.”

A vote for Barack Obama is all but impossible. I am a pro-life social conservative, full stop. Obama is radically pro-choice, even voting against legislation that would have forced medical personnel to save the lives of babies born during botched abortions. The Rev. Jeremiah Wright’s spiritual son is disqualifyingly left-wing on social issues that matter most to me.

As for John McCain, his hot temper and bellicose foreign policy instincts are deeply troubling. America cannot afford the wars we have, much less new ones with Russia or any other nation. Worse, the executive branch has far more freedom to conduct foreign policy than it does domestic policy. And the more Gov. Sarah Palin shares her nitwit nostrums, the less confidence I have that she’s capable of running the country if her elderly boss were abruptly retired by illness or death.

After eight years of GOP misrule from the White House, Republicans don’t deserve to win again _ especially if it’s hard to see how a President McCain would differ meaningfully from the man he seeks to replace. But given the active role Democrats have played in the rolling financial catastrophe, from Clinton-era Wall Street deregulation to water carrying for Fannie Mae and Freddie Mac, they don’t deserve voters’ trust either.

McCain is awful on war. Obama is awful on the sanctity of life. Neither inspires confidence on the economy, nor do their parties _ both of which are up to their eyeballs in culpability for the present economic catastrophe. We all want change, but McCain is not credible on that front, and Obama only offers a fresh new gloss on tired, old Democratic boilerplate.

When neither candidate is tolerable, what does the responsible voter do? Withhold his vote, as a form of civic protest.

In 2004, leading Catholic philosopher Alasdair MacIntyre announced he would sit out the presidential vote because he rejected the Democrats’ hostile stance toward unborn life and the Republicans’ economic policies, which in his view undermined the stability of the traditional family. Dr. MacIntyre argued that not voting in a particular election is a morally just act of resistance to a system that presents us with an unacceptable choice.

Besides, what if McCain won, given the kind of campaign he has run? What will he have been elected to do, except to not associate with 1960s domestic terrorists and crazy-pants black preachers and, to paraphrase Tina Fey, find out what a maverick would do in a given situation and then do it? A McCain presidency would only delay what the shipwrecked conservative movement desperately needs to do: rethink, rebuild and relaunch in light of new realities.

Both parties have run the country into the ground, and I have no faith _ none _ in the leadership class in Washington. With any luck, the 2010 midterm elections will see true mavericks arise from the grassroots of both parties to challenge the incumbents. This year, though, voting in the presidential and congressional contests only gives voters the chance to affirm Washington’s rent-seeking, self-serving status quo.

Granted, anything could happen between now and Election Day that would change my mind. But absent something extraordinary, I’m going to reject both the Republican and the Democrat.

Say what you will, but that will be the first presidential vote I’ve cast, so to speak, that I can truly believe in.