Chief Justice Earl Warren was a popular California Governor before he got elected, and before him several Justices openly participated in politics. Chief Justice John Jay resigned to run for New York Governor, Taft was President before being Chief Justice, Charles Hughes was New York Governor Secretary of State, and actually resigned his seat in 1916 to run for President, and became the only man to serve non-consecutively on the Court. There are more examples, but those are just a precedent.
After Warren, no more politicians served on the court, by whatever means necessary, find some more OTL politicians to serve on the Court. House and Senate members, Cabinet positions, even an ex-President if you can.
After Warren, no more politicians served on the court, by whatever means necessary, find some more OTL politicians to serve on the Court. House and Senate members, Cabinet positions, even an ex-President if you can.