Just How Strong are McCain's Committments?

Dan Stover picked up on this quote from Hugh Hewitt's blog:

Discussing the possibility of a pro-choice veep is fine, and perhaps even excellent politics. Actually picking a running mate who is pro-choice would end the momentum that has been shifting to McCain, and almost certainly destroy the prospect of his winning. Conservatives who have begun to recognize the danger posed by an Obama presidency to the national security of the United States and put their shoulder to the wheel would melt away by the millions as they would see the effective evisceration of the party's pro-life commitment.

If McCain is solidly pro-life, and if upholding the sanctity of life is paramount among his values, then why would he even entertain the notion of nominating a pro-abortion person for Veep???

Would the life issue really be sacrosanct in a McCain presidency? Or would it be "negotiable" or "on the table," to fulfill his need to "reach his hand across the aisle," much like his "commitment" to border security, or to the First Amendment? A choice of a pro-abort for a Veep would render his need to "get along" with the other side to be nothing less than pathological. At any rate, McCain's VP choice will go a long way toward making his true commitment to the life issue clear, one way or the other.

The notion that McCain is merely considering such a pick, if true, flies in the face not only of all things conservative, but of the dignity of humanity itself. This leads one to take a step back in evaluating just who is the real John McCain, and just who or what is he willing to compromise to meet his ends?