Answer:
The Constitution does not say that a Justice must be American born, a certain age, or hold any particular profession before being selected. However, most Justices tend to begin their tenure while in their 40s or 50s and may remain with the court as long as they wish or until they are impeached for improper behavior. Most Supreme Court nominees are personal acquaintances of the sitting President. An overwhelming majority of them attended law school and worked as a lawyer or served as a judge prior to their nomination. In fact, in the long history of the court, most of the Justices held some kind of public office before being confirmed.