We'll probably never have a fully elected SCOTUS where they run for the seat in and have to win primary elections (though that would be my ideal system). A middle ground compromise would keep the current system of the President naming vacancies and the Senate confirming them, but then leaving it up to voters if they want to retain those judges for another term. Ideally, it would curtail senile federal, lazy, and corrupt federal judges from serving for life, and if a judge "evolved" on the court, they could be dumped for their treason.
Illinois has a fully elected judiciary and it works well, although the Crook County court system is effectively a one-party system of getting the job due to buttering up RAT party officials, and those judges are never denied retention (and we vote on dozens of them every election cycle!) Statewide, the judicial branch is probably the best of the three branches (I will continue to say that after "Republican" Rauner took control of the executive branch). Illinois Supreme Court judges are elected by district in partisan elections (I believe Illinois is one of only seven states to do this) and serve for a term for 10 years.
We should have had the IL Court after we won the Southern IL seat in 2004, but don’t cause a rat had won a Republican seat in 2000 (in Western IL) and is still there.
My ideal system for IL Supreme Court would be 3 districts (1 most of Cook, 2 the most GOP parts of Cook and Collar Counties, 3 the rest of the state), Justices elected for 6 year terms, each district having a seat up every 2 years. It would give us a margin of error, allow a rat to win up to 1 GOP seat without costing us the majority. It’s so hard (so far impossible) to beat a Justice in a retention election even though they need 60%. Lloyd Karmeier, our guy in Southern IL, came close to losing last year after a major push.