A quick rehash: Obama has repeatedly said that he doesn’t know when life begins, and apparently hasn’t attempted to get the answer—an investigation, he quips, that’s beyond his “pay grade.” Yet, that uncertainty has not deterred him from advocating embryonic stem-cell research. In other words, he doesn’t know if the embryo is human life, but nonetheless advocates its dissection and destruction for purposes of medical research. I blasted that position as reckless and irresponsible. I granted that I could understand him supporting embryonic research if, say, he was certain that life doesn’t begin at conception—but that isn’t his position.

Well, how about John McCain’s position on conception and embryos?

I’m surprised that no one zinged me last week for not highlighting what, in McCain’s case, might be an ethically worse position. I opened the door from the outset of the article when I quoted McCain’s response to Rick Warren’s question—the same one that Warren asked Obama—at Saddleback Church. Asked when he believes “a baby gets human rights,” John McCain didn’t hesitate to say “at the moment of conception.”

That’s the right answer, no doubt biologically, deserving of the cheers it elicited from the audience, especially on the heels of Obama’s frustrating response. But the follow up was disconcerting, as McCain didn’t repudiate his support of embryonic stem-cell research.

And why not? If John McCain believes that life begins at conception, and that an embryo is thus a human life, how can he morally accept destroying that life over and over again?

The answer is that he sees the potential benefits as outweighing the negatives. This is a classic ends-justify-the-means position. You take lives to help lives, you kill to save.

I couldn’t disagree more.

There’s added information that’s important to consider in McCain’s position, as well as Obama’s: As was pointed out to me by an editor and a medical researcher, current embryonic research authorized in the United States allows (largely, this is complicated) for the dissection of pre-existing embryos that are scheduled to be discarded. (Of course, the embryos are created regardless through in-vitro fertilization, thus generating the excess embryos available to be discarded.) McCain’s position is to permit research on those embryos. Obama supports that research as well, though I’m fully confident he would go much further, very likely opening the floodgates along the lines of the Europeans.

For the record, I’m firmly against that research as well. I’m against the process that led to the “excess” embryos in the first place, irrespective of whatever perceived benefits might accrue from the research—but that’s another debate.

For now, I reaffirm that I continue to be disappointed in McCain’s position on embryonic research—a disappointment I share with many pro-lifers. It’s the one chink in the armor of an otherwise stellar pro-life record by McCain. The Republican presidential nominee has long been outstanding on the abortion issue, in both his record as a public official and through the actions in his personal life, especially his and his wife Cindy’s on-the-spot adoption of a dying girl from Mother Teresa’s orphanage in 1991.

Nonetheless, McCain’s stance that life begins at conception, but embryos can be killed, may be worse than Obama’s position of not knowing when life begins but embryos can be killed. Obama can claim blissful ignorance; McCain cannot.

To his credit, and very importantly, McCain has shown openness in the last 12 months to reconsidering his position. I’ve followed it closely. He has moved from firmly in support of embryonic research to increasing ambivalence, signaling a palpable discomfort and perhaps a shift. He’s better on the issue now than a year ago. His answer to Rick Warren was far from a ringing endorsement.

Of course, from my vantage, he’s also light years better than Obama on life matters generally, particularly in the judges he would appoint. With Obama as their nominee in 2008, the Democrats have really betrayed pro-lifers in their party, in a blatant, brazen way they have never done before. The late pro-life Pennsylvania Governor Bob Casey, a Democrat, must be rolling over in his grave.

Nonetheless, that doesn’t let John McCain off the hook on embryos. If life begins at conception, Senator McCain, then it’s worthy of your protection.

Editor’s note: To read Paul Kengor’s analysis of Pennsylvania Senator Bob Casey’s appearance at the Democratic convention tomorrow evening, written exclusively for the National Catholic Register, click here.