[corygarms]

I assume the 9 years here is to ensure two-term presidents will have vacated office?

[mgrat]

Correct - and incoming POTUS will have to use up political capital to do so.

[tomwheeler]

This is insufficient, since the 22nd amendment only limits the number of terms to which a president can be elected. A president can legally serve longer than that.

For example, consider a president who dies in office a few days into the term. The VP becomes president, serves out the remainder of that four-year term and then be elected for two more terms. The statute of limitations would therefore need to be 12 years or more to have the desired effect.