I came accross the following passage in my textbook:
ゆとり教育で学校で教える内容が減らされたため、その教育を受けた子供達は常識的に誰でも知っているはずのことでさえ知らないという現象も出てきた。
I can understand the meaning of the sentence, as "Due to the decrease of contents taught at school as a result of ゆとり教育, the phenomenon of children who underwent that education and don't know even things that anyone should commonly know, also happens."
Since 誰でも知っているはずのこと is the object of 知らない I would rather say directly:
誰でも知っているはずのことさえ知らない
Without any "で". i.e., if we were to remove the "さえ", it would apply "を":
誰でも知っているはずのことを知らない
I don't understand what is the function of で here. What am I missing?
よろしくお願いします。