I don't understand this sentence. I put placeholders for the names to stay with TC rules.

“(Subject 1) üzerinden siyaset yap?lamayacag'? gibi (subject 2) üzerinden de siyaset yap?lamaz” diyen (person quoted),

It seems to say.

From the fact that the Subject 1 will never happen just as the Subject 2 can't possibly happen",, (somebody) said.

Please explain. Thanks.

You cannot use this subject for politics, also the one who says you can not use "...." for politics.

İt is not a complete sentence, this is what it means but it makes no sense