Reply #18: On the other hand the 25th Amendment is very messy

[ddeclue]

and I think either Obama would have had to have signed over the office temporarily or a majority of the cabinet (not yet sworn in for the most part at that point) would have had to have declared Obama as being incapacitated (which if his powers weren't yet attached until he took the oath then he would have technically been) before Biden would be acting President.

I don't think even the 25th Amendment is the final solution to problems of succession and either some court rulings will have to be made at some point in the future, or there will need to be another amendment passed to further clarify how succession works and these nit picky issues like whether the President's powers attach prior to his taking of the oath or not.

:)