I hate to rain on John McCain's parade right after he trounced Barack Obama at Rick Warren's Saddleback Church forum, for which I heartily applaud him, but McCain's trial balloon consideration of a pro-choice running mate demands a response.

The prospect of an Obama presidency is so horrifying that many conservatives have temporarily put aside their misgivings about McCain to focus on defeating Obama.

They hold their noses on McCain's immigration record, his campaign finance reform zealotry and his newfound acquiescence to the propaganda narrative of environmental extremists. But they are profoundly appreciative of his tougher stance against tax increases and mindful of his undeniable superiority over Obama on foreign policy and national defense. Recent world events, including Russia's naked aggression against Georgia, magnify this already-glaring contrast.

But while national defense necessarily occupies the front burner, McCain would make a fatal mistake to assume that social issues, especially abortion, are ever off an equally blazing front burner for an inestimable number of social conservatives, the Republicans' most reliable voting bloc over the past three decades.

Last Wednesday, McCain "floated the prospect" of picking a pro-choice running mate and said that former Pennsylvania Gov. Tom Ridge would be an acceptable -- and possible -- selection.

He told The Weekly Standard: "I think that the pro-life position is one of the important aspects or fundamentals of the Republican Party. And I also feel that -- and I'm not trying to equivocate here -- that Americans want us to work together."

McCain must quit echoing the Democratic talking point that places form over substance and the illusion of bipartisanship above principle. Who says Americans "want us to work together" if that means abandoning legal protection for the innocent unborn or other inviolable principles?

McCain said: "You know, Tom Ridge is one of the great leaders, and he happens to be pro-choice. And I don't think that that would necessarily rule Tom Ridge out."

With all due respect, Sen. McCain, you may not rule Tom Ridge out, but if you choose him, you're virtually guaranteed of ruling yourself out. You misunderstand this at your electoral peril.

Ridge, on "Fox News Sunday," also revealed his misapprehension of the importance of the life issue to a large percentage of Republican voters when he opined that his pro-choice stance wouldn't make him a liability among conservatives. "The last time I checked, the vice president is not an independent voice," said Ridge.

That woefully misses the point. Not only is the vice president the president's immediate successor if the president dies or becomes incapacitated but also McCain's selection of a pro-abortionist candidate would send a message grossly undermining the Republican Party's uncompromising commitment to the lives of the unborn. Continued...