There's very little chance that a Republican President will have to deal with a Dem Senate, given the current numbers. Regardless, this is deeply irresponsible and would essentially render the Supreme Court impotent. Just goes further to show how Obama and Earnest are perfectly willing to escalate every political conflict to irresponsible levels.
True, but Republicans are highly unlikely to have 60, so they could still try to filibuster any SCOTUS appointments for 4 years. Only a Chief Justice is required in the Constitution, and he's the 2nd youngest. McConnell could nuke it of course, but I think nuking the SCOTUS filibuster will be met with a pledge by the opposition party to add a seat for every time the nuclear option was used, and I expect the 2020 Dem would run on doing just that.
So unless things de-escalate quickly, I think the endgame is de facto parliamentary supremacy at the federal level by 2040 at the latest, because whenever a party wins a federal trifecta, it will just give itself a large SCOTUS majority, House of Lords style. As a fan of the rule of law, I hope things do de-escalate and the worst that comes of this is that Justice Garland or some other compromise pick is delayed until December.
I don't get the add a seat bit. You mean the way FDR tried to pack the court and failed?