"McCain's most dramatic possible play would be the selection of Lieberman -- a Democrat who was only eight years earlier his party's nominee for vice president and, after losing his own party's line in a Senate reelection bid in 2006 and winning instead as an independent, now calls himself an Independent Democrat. In selecting Lieberman, McCain would be doubling down on the central bet of his candidacy -- that aexperience, gravitas, and a willingness to buck the leaders of his own party out of a sense of integrity and what the American people need will trump youth-dynamism-charisma. In choosing Lieberman, McCain can credibly say that he is the candidate of change in 2008 -- a candidate of political change, willing to throw out partisan categories in pursuit of two specific goals."
In a world where McCain did not have to consider a VP based on his geographic or ideological weaknesses, I believe he would pick Lieberman. I also think he may have picked him if Obama selected Chuck Hagel (which seems less likely now than it was a few weeks ago). But as it stands, Lieberman doesn’t give McCain any votes; they have very similar foreign policy positions, and even though Lieberman leans to the left on social and domestic issues, the activist base of the Democratic Party hates the man with a red hot passion. Taking a stroll through Daily Kos and the Huffington Post any day of the week will reassure you of that; these folks are not going to be pulled to his campaign because he has someone on the ticket that supports Democratic initiatives.
John feels that having Lieberman on the ticket will confirm McCain’s willingness to cross political divides to win the war, and this is the strongest case for having Joe on the ticket. Like a lot of us who still fit somewhere on the left, and yet have supported candidates on the right who we generally disagree with on cultural and social issues, to have McCain choose a candidate at odds with his party’s conservative and religious base would speak volumes for his commitment to making the fight we are in a bipartisan effort. It will also piss off that base to no end, and the votes he may lose from having Lieberman on the ticket would likely outweigh those he gains.