Why so that they can become even more isolated from the people just like the president?
Frankly I think SCOTUS “judges” need to live with the edicts they issue, and as far as I know they already have marshal protection.
Because an assassination could easily change the balance of the court depending on who is POTUS.
It doesn’t have to be POTUS level protection but at least something greater than they have now. I was unaware of marshal protection.