[Chloé Palmas]

Well, he can only nominate them once the positions become vacant. Technically he could create new circuits in order to pack the court but that gets both controversial and complicated to explain and implement, too. FDR tried it and they subsequently even imposed term limits on the Presidency.

As for the latter it kind of goes back to a point that Damien and I were making about the ability to render a decision irrespective of political influence ; it should not stop you from impartially interpreting the law / upholding the constitution. Of course it does sometimes arise to the level of which there are conflicts of interest and when ethics arise you trust the justices to recuse wherever relevant.