I'll throw in my 2 cents on Romney's potential running mates.
Never in a Million Years
Sarah Palin: Been there, done that, didn't work. Hasn't been a Romney fan. Too polarizing.
Michelle Bachmann: Brings nothing to the table. She couldn't get Evangelicals or Tea Partiers to help her win a single primary.
Jan Brewer: Absolute lightweight. Makes Palin look like Thatcher.
Rick Santorum: Too polarizing in a general election. Can't stop talking about unpopular social issues. Not enough power to force a "unity ticket".
Newt Gingrich: Beyond making the VP debate a must-watch event, has absolutely no appeal to compensate for his immense baggage.
Ron Paul: There are better ways to keep Paul's libertarian devotees in the party. Foreign policy differences are huge.
Possible but not Likely
Chris Christie: Lack of interest. Not good to have your #2 outshine you. Wouldn't help with women. Has more moderate views than Romney.
Jeb Bush: Another Bush on the ticket would be a distraction. Lacked interest in winnable top spot, would probably have no interest in being #2.
Condi Rice: Has the chops. Lacks the interest. Would be a force if she could be convinced to run.
Nikki Haley: Has taken hits in her home state and couldn't deliver the South Carolina primary to Romney.
Rand Paul: Pulls in Southerners, Tea Partiers and fans of his Dad. Has some baggage and temperament issues.
Paul Ryan: Would probably prefer to stay in House. Would allow Democrats to focus fire on his plans and budgets rather than Romney's plans.
Likely to Be on Shortlist
Marco Rubio: Despite recent statement of disinterest, clearly the top pick. Tea Party favorite, intelligent, articulate. Would help deliver Florida and increase Hispanic vote.
Rob Portman: Great relationship with Romney. Experience in House and Senate and at OMB. Would help in Ohio. Kind of a boring pick.
Bob McDonnell: Conservative governor of Virginia who endorsed Romney at a key time. Big news recently that his approval in Virginia dropped to a mere 53%.
Susana Martinez: Female, Hispanic, and conservative. Popularity puts New Mexico in play. Said she's not interested, but they all say that.
Bobby Jindal: Southern, conservative, incredibly intelligent and hard-working. Very popular in Louisiana and amongst conservatives. Like with Rubio, hard to see a downside to adding him to the ticket.
Brian Sandoval: Popular, conservative, Hispanic governor of Nevada. Like Jindal, he endorsed Perry but has declined to endorse anyone since Perry dropped out.