The Supreme Court just overturned a lower court order which would have forced the Ohio Secretary of State to set up a last minute system to enable county elections offices to weed out voter registration errors based on discrepancies with state motor vehicle and federal Social Security databases - databases that have been shown to be riddled with errors.
In a 9-0 ruling, the Court ordered the Appeals Court's temporary restraining order vacated, because the state GOP "... are not sufficiently likely to prevail on the question whether Congress has authorized the District Court to enforce Section 303 [of the Help America Vote Act] in an action brought by a private litigant to justify the issuance of a [Temporary Restraining Order]." The Court did not rule on the merits of the case (the question of whether elections officials are obligated under the Help America Vote Act to throw out voter registrations based on mismatches with motor vehicle or social security databases), the ruling does mean that Ohio will not see more voter registrations thrown out between now and November 4th.
The ruling is especially important because verifying voter registrations via database (as opposed to requiring voters to present federally recognized ID) can lead to disenfranchisement of legally eligible voters. According to Kim Zetter of Wired:
The law requires each voter to have a unique identifier. Since 2004, new registration applicants have had to provide a driver's license number or the last four digits of a Social Security number to register (voters who don't have them are assigned a unique number by the state). States are required to try to authenticate the numbers with motor vehicle records and the Social Security Administration database.
But databases are prone to errors such as misspellings and transposed numbers, and applicants are prone to make mistakes or write illegibly on applications. The Social Security Administration has acknowledged that matches between its database and voter-registration records have yielded a 28.5 percent error rate.