Not all Democrats are thrilled with Obama there will always be people in both parties who won't be thrilled with a candidate so I'm really not sure what your point here is.
But in Ryan's case, his negatives far outweigh the benefits...
And this is Mitt Romney, master of cost-benefit analysis.
The costs are he scares Old people, which make Florida and Virginia harder to win. He has no foreign policy experience, no military experience, no business experience and has never been a mayor or a governor, so no executive experience. Also, he has extreme views on abortion, wh ich is the last thing Romney needs right now.
The benefits are that he gets conservatives warmed up. But Romney should have already had them in the bag.
Of course, we have no idea what came up about the other guys in vetting.
So much as Romney got the nomination because the other guys were worse, the same might be said for his running-mate.
Offering places in my "LEarning to Live with Obama" seminar for disgruntled conservatives.