Whoa, whoa, slow down. First they need to get rid of this "lifetime" shit. When the President doesn't even get that luxury, something's a little off. I'm fine with appointments being made, but for God's sake, why is it for life? You could theoretically have a Supreme Court that's like four generations removed from the current generation. Think there might be ideological differences that comes with that? And it's not like they have to worry about making unpopular decisions and getting ousted.
Is a ten year cap too much to ask? That would keep a healthy revolving door of bi-partisanship, unless one party just ran away with every election for like forty fuckin' years or some shit, which is HIGHLY unlikely, but even if so, at least the people would be somewhat voting for those appointments.