And we all know how many times these two have tested the constitution. Too many to count I'm sure. I wouldn't put it past them.
Interestingly, the constitution makes not provision for becoming President by ascendancy from VP. It simply states no person can serve more than two terms, saying nothing about consecutive.
Amendment XXII
Section 1. No person shall be elected to the office of the President more than twice, and no person who has held the office of President, or acted as President, for more than two years of a term to which some other person was elected President shall be elected to the office of the President more than once...
ascendancy from VP, if they hold the office/ act for over two years, they can only be elected once. but i agree, you can be bumped into office after having been elected VP by way of resignation or death of pres. or possibly under the specific conditions of XX sec 3, they could be declared pres.