Stacey Friedman remembers the day she got the call from Christine Sun, a lawyer with the American Civil Liberties Union, asking the New York-based Sullivan & Cromwell partner to represent Arkansas families targeted by an anti-gay referendum.

In November 2008, Arkansas voters had approved a ballot initiative — dubbed Act 1 — that made it illegal for unmarried, co-habitating sexual partners to adopt a child. The law was directed at same-sex and heterosexual couples alike. “When you make it broader and pretend it’s not about the fact that they don’t like gays and lesbians becoming parents, it makes it tougher because the law is more mixed,” Friedman said.