Take that to the next level.
How about taxing the...Government ?
For example: I am a teacher. I run for office. I win. Now, as a consequence of my win, my tax bracket for the rest of my life, is 100% after i exceed the higher of either:
a) my elected official salary, OR
b) the average last 5 years of W2 income, OR
c) the average last 2 years of W2 income.
You'd delete inmediately all the grifters getting into government to be rich. And because those narcissists griefters people would self select themselves out of the running; it gives breathing room to those willing to actually do their DUTY for country. Those willing to sacrifice lifetime income.
This is pathway to the less charismatic, but more duty-oriented people that would not mind working in the govt and also do a good job. Under these rules, you dont care if I stay in govt forever, either. Limited terms have no point, when you can't grift.
This also takes care of those pesky post-election speaking fees, as well!