To have the Reps do the same the first chance they get? Where would it end? 20 justices, 30, maybe 50?
Feel bad to be so matter of fact, but RBG died with a R president and Senate. She took a chance and it didn't work out.
In Game Theory it is the loser who gets to decide whether to "accept" the loss or to "escalate." The winner won, they liked winning, and even when the winning is bittersweet the winner does not escalate further.
Are are you arguing the Republicans are "losing" something with putting a Republican on the Supreme Court and have a 6-3 majority?
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Or is your intent of your post not to be an accurate describer of reality but instead to do HUMILIATION much like Senones (a Gaulish tribe) told the Romans Vae Victis.
https://en.wikipedia.org/wiki/Vae_victis
I ask if this was your intent (the humiliation), maybe you should think about this for this tactic did not end well for the Senones