In 1991, Bolick and Chip Mellor (his former boss from the Mountain States Legal Foundation) co-founded the Institute for Justice with funding from Charles Koch. He was the Vice President and Director of Litigation from 1991 until 2004. The organization litigates on behalf of small businesses faced with regulations that it views as unjustified or anti-competitive. It also promotes school choice, property rights, and free speech. Bolick and the institute were active in defending a Cleveland, Ohio school voucher program, which was declared constitutional in a 2002 Supreme Court case, "Zelman v. Simmons-Harris" The court ruled in favor of a Cincinnati, Ohio school voucher program, allowing the use of public money to pay tuition at private and parochial schools.