I already mentioned here on this forum the "trias politica" (the separation of powers) in a thread about constitutions:
https://reshistorica.forumotion.com/t1308-constitutions-mmmmm
Due to the actuality, also here in Belgium with a lot of fuss about the proposal of a nomination for the judicial branch, I try to start a thread about the history of the "trias politica" and how independent the three branches are from each other. In this case the independence of the "judicial power".

Perhaps it is interesting as an introduction to read first this chapter, as I did, about the introduction of the idea into society in connection with Montesquieu, most referred to on this question.
https://oll.libertyfund.org/pages/montesquieu-and-the-separation-of-powers.
And I have the impression that the idea was still in "statu nascendi" and only later was refined and applied in real in government systems?
And about the growth of the idea of the separation of powers in 17th century Britain I read this afternoon and learned from it:
https://scholarship.law.upenn.edu/cgi/viewcontent.cgi?article=8996&context=penn_law_review

I thought that what happened in the US about a kind of politicisation of the judicial branch of the "Trias" or perhaps more mildly explained as a political affiliation of the members of the Supreme Court and hence perhaps a political bias in their judgements was specific to the United States.
https://en.wikipedia.org/wiki/Appointment_and_confirmation_to_the_Supreme_Court_of_the_United_States

As I understand it:
The judges of the Supreme Court are proposed by the President and the Senate confirms them and allows the President to appoint them.

But as I did research for instance for Belgium I found out that that system was not that specific for the US, but nearly the same in the case of Belgium.

https://en.wikipedia.org/wiki/High_Council_of_Justice_(Belgium)
It is more elaborated in the Dutch language wiki and if MM is interested i am nearly sure that there is a French equivalent.
https://nl.wikipedia.org/wiki/Hoge_Raad_voor_de_Justitie
One of their tasks (in comparison with the US President) is to propose members of the Supreme Court.
From the wiki:
""Objectieve benoemingen" en gepaste opleidingen van het personeel."
""objective nominations" and appropriate training of the personal"
 
And then 
https://en.wikipedia.org/wiki/Court_of_Cassation_(Belgium)
From the wiki:
"The minister of Justice will then send all candidacies to the High Council of Justice of Belgium, who will nominate one candidate. The Belgian federal government (officially "the King" as the personification of the executive) will then finally appoint or reject the nominated candidate."
 
In my opinion doesn't that system differ that much from the US system about the political affiliation of the judges, as via the High Council of Justice the judges are appointed by a High Council, whose members are chosen each four years half by the Belgian magistracy (already from their appointment political affiliated) and the other half by the complete Senate with a two thirds majority.

Although I have to confess after comparising that the Belgian system is perhaps safer to avoid political appointments?

And my final conclusion after all my reading would be that both and the US and the Belgian system are not that bad n the field of "the separation of powers" and in the politicizing of the judicial system? Perhaps Belgium a bit better than the US?

Paul.