[cnn-photo-caption image= http://i2.cdn.turner.com/cnn/2008/images/08/03/art.obama.afp.gi.jpg
caption=" Virginia Gov. Tim Kaine could be in the running to be Barack Obama's VP."]
(CNN) - It happens once every four years: Political pundits, news junkies and water cooler crowds obsess over whom the presidential contenders will pick to be their No. 2.
sked by CNN's Howard Kurtz what drives the compulsion behind the "glorified guessing game," A. B. Stoddard, an associate editor at The Hill, said every journalist is hoping for a "James Bond moment" when he or she can be the one to expose the story.
That, she said, "obviously never happens."
"But it comes in a lull in the campaign - June and July. You know, the primary is over. It tends to get a little dull. Usually the negative ads ... haven't appeared yet, and so it's sort of a perfect time to begin the guessing game.
"It is their first presidential decision," she said on CNN's "Reliable Sources."
Roger Simon, chief political columnist for Politico.com, said another benefit of dangling names in front of the public is that the candidates can use the media to vet those in the running.
"If there's anything is some guy's closet ... some local reporter who has covered this person for eight or 12 or 16 years might know about and might it get out before the candidate has committed to an embarrassing choice," he said.
Before the 1980s, presidential candidates typically did not unveil their running mates until the convention, often on its very last day.