the judiciary act of 1869 sets the number at nine.Exactly, there has to something preventing it
Judiciary Act of 1869 - Wikipedia
but this is just legislation. Congress could pass legislation to expand the court to whatever number they want because the Constitution does not specify this.
i think republicans haven’t done this because they don’t want to cross a rubicon where when the next party is in power, they just appoint more justices etc. under normal circumstances this would be true of the democratic party as well, but i think republicans have already crossed the rubicon because of how they handled the garland nomination and now this coney barrett nomination


barrett just had to sit there and take it while kamala called her immoral