McCain and his advisers must keep in mind the harsh political reality: In this toxic environment for the GOP, McCain is the clear underdog. Both he and Obama have obvious weaknesses, but Obama's (lack of foreign policy wherewithal) could be addressed by the choice of a Joe Biden or Jim Webb.
It's a somewhat risky proposition, but in this corner of the internet, McCain is encouraged to move toward the center with his choice. He gains nothing by choosing Mitt Romney or Rob Portman, as voters in Pennsylvania, Missouri, Wisconsin and other states with large swaths of Reagan Democrats will react ambivalently. Although both Romney and Portman would shore up McCain's support among core conservatives, simply reinforcing his base is not a winning strategy. The number of self-identified Democrats significantly outnumbers the number of self-identified Republicans, and McCain must be mindful of such.
Iraq, Katrina, Schiavo, Abramoff, DeLay, Craig, Vitter -- each word holds a dreadful connotation for the GOP. Obama's base is simply much larger than McCain's, especially in this political environment. So McCain must gamble. He must reinforce his national security and pro-life credentials to conservatives (NARAL-Pro Choice America has given the Senior Senator a lifetime rating of 4%), but simultaneously needs to reach out to disenchanted HRC supporters, blue-collar voters, Hispanics and the growing crowd of centrist Democrats like the Chairman who are wary of Obama's extremism. McCain must capitalize on his bipartisan appeal. It's the only way he can win.
Obama, mindful of McCain's cross-party appeal, will make every attempt to tie McCain to Bush in an effort to bury him. By choosing a running mate who, like Rice, Ridge or Bloomberg, has a centrist record and bipartisan appeal, McCain pushes Obama further left. Similar to how HRC consolidated the relative centrist Democratic core and painted Obama as an elitist, McCain must highlight his well-deserved maverick, bipartisan reputation and make a statement about the kind of administration he intends to run. After choosing a centrist running mate, he must highlight Obama's laughable extremism (further left, according to the nonpartisan National Journal, than self-avowed socialist Bernie Sanders) and empty rhetoric. McCain must brand Obama "liberal" and dismantle his mindless rhetoric, a mere house of cards. By staking a claim to the political center, McCain can push Obama to the left and force him to run on his record. If he is able to do this, he will have given himself a chance.