In the United States, the Supreme Court ruled on the constitutionality of single-sex public education in the 1996 case of "United States v. Virginia". This ruling, written by Justice Ruth Bader Ginsburg concluded that single-sex education in the public sector is constitutional only if comparable courses, services, and facilities are made available to both sexes. The No Child Left Behind Act contains provisions (sections 5131.a.23. and 5131c, 20 U.S.C. section 7215(a)(23), and section 7215(c)) designed by their authors—senators Hillary Clinton (D-NY) and Kay Bailey Hutchison (R-TX)—to facilitate single-sex education in public schools. These provisions led to the publication of new federal rules in October 2006 to allow districts to create single-sex schools and classes provided that 1) enrollment is voluntary, and 2) comparable courses, services, and facilities are available to both sexes. The number of public schools offering single-sex classrooms rose from 4 in 1998 to 540 in 2010, according to the web site of the National Association for Single Sex Public Education.