I’m not sure you’re right about Marco Rubio being ineligible.
When the Constitution was first written, nobody ran for VP – only president (II.1). Hence, anybody in the running had to be natural born. The candidate with the most electoral votes became president, and the one who finished second became VP (unless there was a tie for second, etc.). I’m paraphrasing, but that’s my take away.
But then, with the passage of the 12th Amendment, people voted separately for the president and vice president. The 12th, unfortunately, doesn’t address qualifications for VP – unless I’m overlooking something. An oversight, I’m sure, but them’s the breaks.
Now, here’s the rub. Suppose, for whatever reason, the VP has to assume the office of the presidency!
So, you tell me – is Rubio eligible or ineligible?