The authors of the Constitution did not intend SCOTUS to micromanage local election procedures so they could make it harder for the old and sick to vote. But SCOTUS just decided they wanted to. https://twitter.com/steve_vladeck/status/1319072235454402561

In a few places (Section 4 of Article I, Section 2 of the 15th Amendment, and Section 2 of the 19th Amendment) specifically gives to Congress, not SCOTUS, the power to pass laws governing election procedures. Nowhere was it envisioned that SCOTUS would micromanage elections.

After removing preclearance from the Voting Rights Act, based on no Constitutional text and in violation of Section 2 of the 15th Amend, SCOTUS has increasingly taken on a form of preclearance power for itself, again based on no Constitutional text. https://twitter.com/jonmladd/status/1315303257359757312

I can't emphasize enough how the Republican SCOTUS majority's key modern voting decisions (Bush v Gore, Shelby Count v Holder, a million shadow docket rulings) are based on no Constitutional text or pre-existing Constitutional principle. They are just made up.

They try to rationalize them by making up new Constitutional principles or tying the decision to some existing principle in a way that has never been done before (Bush v Gore said doing a recount of an election would violate the equal protection clause). It's all made up.