it is not his parents,as I see it,that influence him so much as 这个that 引导的是什么从子

it is not his parents,as I see it,that influence him so much as 这个that 引导的是什么从子
it is not his parents,as I see it,that influence him so much as 这个that 引导的是什么从子

it is not his parents,as I see it,that influence him so much as 这个that 引导的是什么从子
that引导定语从句,用来修饰parents.
It is not his parents.it 是形式主语,is not 是be 动词,his parents 是表语.
As I see it是插入语,不影响整个句子的任何结构.
整个句子与his parents don't influence him so much.比,强调了his parents.

我觉得应该是主语从句吧？

你好
在你的句子里，that引导强调句。同时that指代parents,做强调句部分的主语。
祝你愉快。

是定语从句

强调句