If the 3 branches all go red can a law be passed making 9 the final number of supreme court justices? If so, would they even do it?
https://www.nationalgeographic.com/history/2020/09/why-us-supreme-court-nine-justices/
But as the past is prelude: if Republicans controlled all 3 branches of government, they won't do anything. If Democrats were to control government, they would immediately pack the courts.