John Marshall is widely revered as "the great Chief Justice," but before joining the Supreme Court in 1801 he had never served a day in judicial robes and lost the only case he argued at the high court.

Earl Warren had worked for 18 years as a prosecutor and was three times elected governor of California. But he had no prior judicial experience. Nor did William Rehnquist, Felix Frankfurter, and Louis Brandeis. Who is qualified to sit on the Supreme Court is a determination made on a nominee by nominee basis by at least 51 US senators. There are no set rules for qualification. Although every past justice has been a lawyer, 41 of the 109 justices had no prior judicial experience.