This is why I advocate for a "what's good for the goose" approach for ratings/evaluations: politicians should also be subject to termination if measures of their success are less than effective. Childhood health, poverty, employment, median income, crime, quality of life...fill in whatever is important (number of wealthy friends/supporters does not count here).
The claim that outside of school factors can be overcome by magical inspiring teachers is great stuff for movies and one-in-a-million stories, but even those become more rare as the reform zombies look for other ways to profit (after jobs were slaved away to Asia and the middle class home-owner market was bled dry). Stand our ground. Surely if one lonely public school teacher (charters and private schools won't have to take the most challenging kids)can be expected to climb this mountain, then a well connected politician can climb one of their own.