National civil rights groups including the Anti-Defamation League and the Asian American Legal Defense and Education Fund explain that denying same-sex couples the right to marry is not merely a denial of the collective rights and duties that married New Yorkers enjoy, but a denial of due process and equal protection of the State’s laws. Amici demonstrate that granting civil marriages to same-sex couples is the only remedy that can redress this constitutional violation. Simpson Thacher & Bartlett LLP is counsel for amici.