In Lane v. Wilson (1939), the Hughes Court struck down an Oklahoma law that required those who previously were not registered voters to register under a two-week window or forfeit their voting rights. The Court noted that Oklahoma’s previous grandfather law provided that those citizens whose grandfathers were eligible to vote could vote themselves, and all others could not. Obviously, this had the effect of disenfranchising African American voters. The Supreme Court had invalidated this system in Guinn v. United States (1915). In response, Oklahoma passed a new law that provided that those previously not eligible must register within this two-week period.

The Court, in an opinion written by Justice Felix Frankfurter, viewed this law as violative of the Fifteenth Amendment by a 6–2 vote. (Justice William O. Douglas did not participate.) “We believe that the opportunity thus given negro voters to free themselves from the effects of discrimination to which they should never have been subjected was too cabined and confined,” Frankfurter wrote.