You are correct it should not be this important. The founding fathers were brilliant but they made a huge mistake by not putting a constitutional check on the Judiciary. The only recourse is the nearly impossible task of an amendment. It’s a ridiculous amount of power to give 5 unelected people. The rats were making the packing threat months ago and they will try it whether Trump replaces RBG or not if they get the power to do so.
The Constitution held for 200 years. When FDR tried to pack the court in 1937 by the same method Holder is threatening, members of his own party denounced him. Today we have a completely despicable dem party.