In 2013, the North Carolina legislature passed a bill restricting ease of voting. Specifically, it eliminated a lengthy early voting period; it ended the ability of 17-year-olds to pre-register (so that they would automatically be on the rolls as of their 18th birthday); it ended the ability of voters to cast a provisional ballot away from their home precinct; it ended same-day registration; and it required voters at the polls to show photo-ID (on the ID issue, the 2013 law had been very strict, but in 2015 the legislature had softened it and let voters who swore they could not get such ID vote anyway).
On July 29, 2016, all of these restrictions were enjoined by the 4th Circuit. On August 31, the U.S. Supreme Court refused to upset the action of the 4th Circuit. The case in the U.S. Supreme Court is State of North Carolina v North Carolina State Conference of the NAACP, 16A168. The state had asked for U.S. Supreme Court action on August 15. The U.S. Supreme Court had asked the NAACP to respond by August 25, and the NAACP complied. So, after pondering for six days, the U.S. Supreme Court split 4-4 on whether to sustain the 4th circuit. In a tie, the ruling of the lower court stands.
It happens that all three members of the 4th circuit panel had been appointees of Democratic presidents. If, by chance, the 4th circuit panel had consisted of Republican appointees, probably the 4th circuit decision would have gone the other way. Then, if the NAACP had asked for U.S. Supreme Court help, that vote surely also would have been 4-4. This case illustrates that having a U.S. Supreme Court with only eight members causes outcomes to be determined by the Appeals Courts, and by the random events that determine which judges get any particular case. Thanks to Rick Hasen for the news.