When you choose a person as your partner on a presidential ticket, what are you saying about that person? If you're acting honestly and in the best interest of the American people, you're saying that he or she is the second most qualified person in the country, after you, to be president. (Or, to bow somewhat to political realities, you are saying he or she is the second most qualified person who also happens share your ideological leanings.)
That's why it is completely absurd that on Sunday, John McCain wouldn't tell an interviewer that he would support Sarah Palin if she chose to run for president in 2012, saying "I can't say something like that. We've got some great other young governors." McCain cited Tim Pawlenty of Minnesota and Jon Huntsman of Utah. Why, then, wasn't Pawlenty or Huntsman his choice for VP?
Let's get real. In 2012, McCain is going to endorse someone for the Republican nomination who is hawkish on foreign affairs but socially and environmentally moderate. He'll endorse from the point of view of 2000 John McCain instead of 2008 presidential election John McCain. He most certainly will not chose someone who is a rabid right-wing fundamentalist Christian.
Meaning he won't endorse the person he wanted to install in the White House just a few short months ago.