Voting rules are a bit of a judgement call for the Supremes

 I would think Due Process means the local election authorities cannot suddenly alter the vote collection process right before the election.

In California the repub put out their own drop boxes. Kind of stupid, but  there was no law against it. The California election authorities cannot suddenly intervene and remove the boxes a few weeks before the election.  They did not, had some sense.

The Pennsylvania ruling extending the vote counting deadline because of slow mail is not a sudden change in vote collection. Mail in votes were still validated by post mark. The Texas effort to suddenly remove county drop boxes is a violation.

A bit of a judgement call, maybe, but it is a simple process and there is no way a bunch of Conservative Supremes foul up the Pennsylvania rule with the aide of stupidity. Something is wrong in the Supremes and we are paying a long term price in 'make stuff up' law jamming the courts.