The Supreme Court started with 6 justices.

That would have changed to 5 after 1801, but it was changed back to 6 in 1802 before a vacancy occurred.

It got changed to 7 in 1807, 9 in 1837 and 10 in 1863. In 1866, Congress decided to cut it back to 7 through attrition... https://twitter.com/TheRealHoarse/status/1315060239423635456

…and that got it down to 8 before Congress changed their minds and set the number at 9.

So it’s not like the size of the Supreme Court has been set in stone, nor have other courts. Congress has dicked around with the numbers when they want to hold a president in check...

…or let a president name more justices.

This is why we have a system of checks and balances (in theory), and not a “we do it the way we always do” law, since we do very little the way we always did.

But, as has been a tradition itself, the GOP is fond of declaring traditions that must be adhered to when it benefits them, and ignoring them when it doesn’t.

The will of the people is, apparently, only meant to bind the other folks.