The Arizona Legislature passed the Arizona Citizens Clean Elections Act (the Act), a law that allowed candidates running for state office who accepted public financing to receive additional money from the State when a privately-funded opponent and independent expenditure groups (groups) spent money. Once a publicly-financed candidate spent a certain amount, he thereafter received roughly one dollar for every dollar spent by an opposing privately-funded candidate or group under the law’s “matching funds provision.” The Arizona Free Enterprise Club’s Freedom Club PAC, several candidates running for state office, and others (collectively Plaintiffs) challenged the constitutionality of the law and claimed that it infringed their right to free speech under the First Amendment. Plaintiffs brought suit in district court against Ken Bennett, Arizona’s Secretary of State and others (collectively Defendants). The district court issued an injunction against implementation of the law and held that the Act substantially burdened the free speech rights of privately-funded candidates and groups without a compelling state interest. The court of appeals reversed and held that the matching funds provision imposed only a minimal burden on First Amendment rights in furtherance of a compelling state interest, namely to reduce political corruption. The U.S. Supreme Court granted certiorari to review.