Ezra Klein makes the case for Lieberman as veep:
...if McCain wins with Lieberman, he wins as John McCain, uniting figure. Not as the next Bush. Not as the Republican candidate. McCain's definitely a hardline conservative, but he clearly aches to be understood as a maverick. How much the better if his win could be attributed to that reputation rather than to some smartly negative ads and brazen supplications before Rick Warren. A Lieberman pick, in other words, lets John McCain campaign -- and possibly win -- on his terms, which has to be an appealing prospect. And as Obama is still ahead, and flusher with cash, and discovering an open line of attack on McCain, and suddenly armored on foreign policy, it's not as if McCain's current strategy is proving such a startling success that he can draw a straight line from here to the White House.