You know how drivers over 60 have special restrictions put on them, and they need to get tested every few years to make sure they aren't going blind or senile? Perhaps our politicians should have to undergo similar testing, since their mistakes could potentially kill more than any car crash could.

Politicians do get tested every few years - it's called an election. If their constituents think that no politician should remain in the job longer than 12 years, they already have the power to enforce that belief by voting them out. You could argue that a Supreme Court position should not be for life so that it takes less than death to remove a judge who has become unfit to hold the position, but you're not trying to convince people if you end with "leftists are god's mistakes."