18,793 diaries stating Hillary should be VP later, the reasons given are all still pointless.
There are only two reasons of any validity to pick a VP, one good, one mediocre but possibly necessary. Hillary just doesn't satisfy either.
So what are the two reasons? Let's start with the mediocre but expedient one.
You as presidential candidate (the only person doing the choosing) honestly believe your chances of winning are no better than even, so you need to pick someone who can supposedly deliver enough votes to put you over the top. Yes, it's the same old 50% +1 strategy.
So does Hillary increase or decrease Obama's chances of winning? I don't know, but I bet Obama does, and his staff have no doubt been pulling data for at least weeks if not months to allow him to decide that if need be.
The pros: She brings along whatever small fraction of her supporters would only vote if he puts her specifically on the ticket along with her. She does not bring the Republicans who voted in operation chaos. She does not bring the racists who will simply not vote for a black man. And most importantly, she does not bring the overwhelming majority of her supporters, who are smart enough to realize that McCain would be a disaster and so will vote for Obama anyway.
So I guess that should be 'the pro', singular.
The cons: Well known extremely high negatives, with a tendency to increase Republican turnout. Turns off whatever fraction of the country that is sexist but not racist. Turns off whatever fraction of the country that is prudish and felt WJC should have been impeached, since they won't seperate WJC and HRC in their disdain.
I'll save the rest of the cons for the good argument for choosing a running mate, but there are likely more cons than pros even at this stage of the game.
So what's the really good reason to choose a running mate?
Well, if you've got the ego to run for President in the first place, then you fell your judgement on what is best for the country is better than any one else's, otherwise you'd bow out and let the better person take the ring. So the really good reason to choose a VP is to select the person you WANT to take the job if you get shot, hit by a bus, or collapse from a heart attack.
The person who shares your vision of the best way forward for the country. The person whose goals, strategies, tactics, and style of leadership are most like yours, given that you believe you way is the best way.
I think it's obvious to anyone who was awake during the race that Hillary Clinton does not share his style of leadership, his strategies, or his tactics. She may share his goals, at least in part. As many have pointed out, the difference between them is more in how they would lead the country, not in specific policy in many ways, although Obama is certainly much more openly for diplomacy and Hillary much more unabashedly a hawk.
So Hillary fails that test too.
The only reasons that should matter to a President do not point towards Obama choosing Hillary as his VP, just like the only metric that mattered in choosing the presidential nominee, delegates won, did not. Just as she saw this, and pushed forward metric after metric that were not the real way a nominee should be chosen to try and explain why she should be the nominee, so do those who have invested her with their time, their hopes, their energy put forward reason after reason as to why she should be VP, in the hopes of salving their pain from losing the race.
It's understandable, just as it was understandable that Hillary kept trying any metric she could to tilt delegates to her side. She believed her vision was better for the country, so she fought tooth and nail to win the nomination. Thus do her supporters, who believe in her, fight equally hard to try and get her the VP slot.
But no matter what other reasons they offer - history, unity, electoral maps, they all fall short of being the one good reason he should choose a VP. To select the person who would lead the country best (in his opinion) if he becomes incapable.