The media link at Fox News.

However, the best information comes from this press release from the Texas Office of the Attorney General:

At issue is whether the interim maps imposed by a three-judge redistricting panel violate the U.S. Constitution and federal law, and exceeds the proper role of the judiciary. The State of Texas alleges the panel improperly rejected the will of the elected legislature and redrew the State’s House and Senate districts without regard to any established legal or constitutional principles.

Attorney General Greg Abbott explained that a stay of the election process is needed because “elections should not proceed based on legally flawed maps that are likely to be overturned on further review.”

The release also included this important addition about the team that hopes to argue to the Supreme Court.

Additionally, General Abbott announced a significant addition to the appellate team that will be representing Texas at the U.S. Supreme Court. Paul Clement – one of the nation’s foremost appellate lawyers and former Solicitor General of the United States – is assisting the State of Texas with the redistricting challenge. Mr. Clement served as the Solicitor General of the United States from June 2005 until June 2008. In that capacity, he was the chief appellate lawyer for the United States and had primary responsibility for appellate arguments to the U.S. Supreme Court. He has argued over 50 cases before the U.S. Supreme Court and has argued more cases since 2000 than any other advocate.