The South Dakota state legislature on Tuesday passed a bill that would require public school students to use the bathroom, shower and locker room that correspond to their biological sex. If Gov. Dennis Daugaard (R) signs the bill, as expected, South Dakota would become the first state to enact such a law. The bill has provoked outrage from gay and transgender rights activists, who say it discriminates against transgender children. They say that it could put schools at risk of lawsuits; in 2014, the Education Department issued guidance finding that Title IX, the federal law that requires equal treatment of the sexes in schools, requires that students be permitted to use facilities that match their gender identity. But the bill’s proponents have argued that the legislation actually matches up better with the original language of Title IX, which requires separate facilities for the sexes. They say it respects privacy while also meeting the needs of transgender students by requiring that schools allow them to use private facilities, such as a teacher’s or nurse’s bathroom.