Nobody asked him to “overturn the election”
All they asked him to do was postpone giving the count his ‘certification’ until significant outstanding issues had been examined.
Look at “200 Mules” for an example.
So a Federal court challenge in these cases could involve the absurdity of State A (which allows "ballot harvesting," voting by mail, and absentee voting for weeks before Election Day) challenging the election results in State B (which only allows in-person voting on Election Day) because State B had the audacity to ignore cases of "ballot harvesting" -- which is perfectly legal in State A -- in a presidential election.