I don't support FDR's attempt to do it, as much as I admire him, and I don't support current attempts. While the number of Justices isn't mandated, changing it at this point just makes it look like you're gaming the system.

I DO support term limits for Justices, ten years seems appropriate. And we ought to solidify the rules for approving them so that scumbags like Mitch McConnell can't game the system to get their guy on-board.

But changing the number? I don't see the need for that.