'Could' is the key word here.
Could it happen?
Sure.
Theoretically, there are very few things that fall outside the realm of 'it could happen'.

However, 'will' is far more definitive.
WILL it happen?
Nope.

Come November we will be voting in a contest between Barack Obama (D) and John McCain (R).

I, for one, am voting for the one with the (D) next to his name.  ;)
Something tells me that the majority of my fellow Americans will be doing the same.
I look forward to President Barack Obama.
:)