The Obama campaign ought to be framing the Palin decision as a comparison between the two candidates' Presidential decisionmaking.
Barack Obama made a very deliberative decision, knows Joe Biden well, worked with him, had him completely vetted. There was no chaos that arose with, or after, the Biden nomination, and it was widely praised on both sides of the aisle. Biden can, and everyone knows he will, talk bluntly and knowledgeably.
By contrast the McCain decision was impulsive, it was defensive, it showed him to be controlled by the rightwing Evangelical wing of the party, she was not well-vetted. He barely knew her (even the executive of a small company meets several times with a prospective Vice-President), she has no expertise that can be used to challenge McCain in his decisionmaking. In her very first statement as the nominee, she lied about her opposition to the "bridge to nowhere."
Let the news media and bloggers ferret out her past. Whatever is discovered will only make the first Presidential decision to choose Joe Biden that much more comforting than McCain's first decision choosing Palin.
The Obama campaign should focus entirely on the 1st Presidential Decision question.
The Republicans are doing what they can to undermine peoples' trust in Barack Obama. The Obama campaign does not have its narrative about John McCain, except recurrent salutes to his service to the country. All that does is reinforce peoples' trust in McCain. Enough of that already, please.
But, the Democrats need to go a step further. They cannot allow McCain's narrative about himself to go unanswered by their narrative about him. Right now, there is no narrative about McCain, only that his policies are a 3rd Bush term. But, they have been at that for months now, and McCain is getting about 15-17% more than Bush's approval.
Without suggesting this strategy stop, more is needed. The Democrats need to tell a narrative about McCain himself. Otherwise, that 15-17% will persist, and may grow. McCain has written ("Worth Fighting For") and recorded it in his own voice, that he runs for President not to accomplish reforms or even for patriotism, but because it is his personal ambition.
If you knew that your President cared only about his personal ambition, and said so, can you TRUST him to make decisions that will be for the good of the country? That should be the theme.
Picking Palin fits that theme. He wanted to create waves, not help him govern, and he surrendered his own personal preference to the evangelical right wing. As a 72 year old with recurrent cancer, he told the country he was willing to risk leaving us to Sarah Palin.
McCain did more. He convinced the entire country that he would overturn Roe v. Wade. Indeed, Sarah Palin, who could become President, opposes a women's right to choose even for rape or incest. She would deny women the very choice she had to carry her Downs Syndrome child to term.
Can John McCain as President, whose goal is his own personal ambition, be trusted to serve the interests of the American people? That ought to be the question the Obama campaign raises based upon McCain's words and his actions.
McCain's first Presidential decision shows the American people cannot trust him to act for them.