While the Democrats dally, John McCain looks for a best friend.

With the Democrats consumed by the final laps of their nominating process, John McCain is planning his fall campaign—and starting to meet with potential running mates.

Like every presidential candidate before him, McCain will look for someone who complements his strengths and offsets his weaknesses. He could use the pick to help raise money, secure the Republican base or attract new voters. But primarily, he will look for someone who feels right—at least to himself.

There’s no shortage of possibilities: Mike Huckabee recently announced that he’d love to be VP, and Mitt Romney has been only slightly more subtle. But losing in the primary season, particularly losing early, has rarely been a good path onto the national ticket.

Our fun interactive graphic gives you the pros and cons of selecting one of the leading six candidates for McCain’s VP.

What will McCain look for? The senator’s national security experience suggests he’s likely to pick a nominee whose expertise is domestic social or economic policy. Former Office of Management and Budget head Rob Portman might fit the bill.

Since McCain is from a Western state, he might look for a candidate from a big Midwestern or Southern swing state. Texas Gov. Rick Perry comes to mind, as does McCain’s buddy Florida Gov. Charlie Crist.

Political ideology is another test. According to Joel Goldstein, author of The Modern American Vice Presidency and a professor at Saint Louis University School of Law, McCain might use his VP choice to send a message to conservative Republicans that “even though I’m a maverick, I’m really one of you.” If so, Minnesota Gov. Tim Pawlenty or South Carolina Gov. Mark Sanford could move to the top of the list.

However, the maverick in McCain might think the best antidote to Barack Obama is a ticket that appeals to independents. And what could be more maverick than choosing Sen. Joe Lieberman of Connecticut, a Democrat-turned-independent (who was Al Gore’s running mate in 2000) as the Republican vice presidential nominee?

McCain’s biggest need might be for someone who is, well, presidential. If elected, McCain would be the oldest first-term president in history, and adding someone to the ticket who could move into the Oval Office if the worst happens might be critical to voters. “You can’t put somebody on the ticket simply because they are from a big state, or a particular demographic group or are popular with one wing of the party, if they are not going to be perceived as presidential,” said Goldstein.

Once McCain narrows the field, his team will run endless background checks to examine every skeleton in the VP nominee’s closet. And, sometime well before the Republican convention on September 1, McCain will roll out his choice for the public to judge.

“There will always be someone who says that that is an inspired choice, that it is a safe choice and that it is a reckless choice,” said Timothy Walch, editor of At the President’s Side: The Vice Presidency in the Twentieth Century. “Only time will tell...you just don’t know until they get on the campaign trail.”

Take the test: weigh in with other FLYP readers on who you think McCain should pick for his running mate.