I dunno.
I think he might do it when he loses though.
It will make the 2000 election aftermath seem like a small claims court case.
The petulant left will threaten violence, discord and inflame racial animosities in an effort to have O seated for a second term, or, barring that, attempt to delegitimze Romney in the eyes of as many as possible (i.e. "selected not elected.).
It's already in their playbook and they have 2000 as a model.