How is he barred? I’d really like to know the section which bars this. My understanding is there is a preclusion from both Pres and VP candidates being from the same state and a limitation of Presidential terms to 10 years, but I’ve never heard anything about not being able to be a VP.
no person constitutionally ineligible to the office of President shall be eligible to that of Vice President of the United States...
The VP must be qualified to serve as President. Since Bill is term-limited out, he isn't qualified to serve as President, and therefore, cannot be chosen as the VP mate.