Erwin Chemerinsky in the ABA Journal:

At the beginning of American history, the Supreme Court was required to hear every case brought to it. Over time, Congress modified these statutes, most recently in 1988, so that today the court has mandatory appellate jurisdiction only when Congress requires that a case be heard by a three judge federal district court. The Voting Rights Act requires this for challenges to the drawing of election districts. But mandatory Supreme Court jurisdiction makes no more sense here than in any other area. Congress could change this to have appeals in voting cases, like in all other matters, go first to a United States Court of Appeals and then to the Supreme Court.