Why don’t you tell us what the D of Ed should be doing and what is its value proposition?
1. It should work towards ensuring we have an educated citizen population in order to make a democracy work (I'm not even sure that's possible in a nation the size of ours, though).
2. It should be funding and guiding research--actual, honest to god scientific research--into the best pedagogical methods for math and reading and later other subjects, along with the best, useful, and most efficient methods of evaluating students' and teachers' performance.
3. It should encourage the development of ideologically neutral curriculums that are engaging, rigorous, and informative.
4. It should be facilitating communication and cross-talk between K-12 schools and the trades and other, non-academic job settings to ensure education can turn out good citizens, ensure the nation's leadership in being an educated and technological superpower, and provide people useful to the work force at all levels.
Regarding at least (2) and (3), it is downright silly to think that local school boards or administrators can do this on their own. It's more akin to an R&D problem that requires a long-term committment with no assurance of profitability.