"It EXPLICITLY says if you can't be elected president, you can't be elected VP! That's the point of the 12th Amendment!"
That's not what the 12th amendment says. The 12th Amendment says that no person constitutionally ineligible to the presidency shall be eligible to that of the vice presidency. Some people argue that if you are ineligible to be *elected* president, you should be ineligible to be *elected* VP. But that's not what the 12th Am. says---only if you are ineligible to *become* president are you ineligible to *become* VP, and the amendment does not require any additional qualifications for being elected VP. So Clinton could be constitutionally elected VP, and if the president died he would become president again. It's not going to happen, but it's not unconstitutional.