A statute prohibits appellants, two national banking associations and three business corporations (Ps), from making contributions or expenditures or the purpose of . . . influencing or affecting the vote on any question submitted to the voters, other than one materially affecting any of the property, business or assets of the corporation. A corporation that violates it may receive a maximum fine of $50,000; a corporate officer, director, or agent who violates the section may receive a maximum fine of $10,000 or imprisonment for up to one year or both. Ps wanted to spend money to publicize their views on a proposed constitutional amendment that was to be submitted to the voters as a ballot question at a general election on November 2, 1976. The amendment would have permitted the legislature to impose a graduated tax on the income of individuals. Ps argued that § 8 violates the First Amendment, the Due Process and Equal Protection Clauses of the Fourteenth Amendment, and similar provisions of the Massachusetts Constitution. They prayed that the statute be declared unconstitutional on its face and as it would be applied to their proposed expenditures. The Supreme Judicial Court upheld the constitutionality of § 8. Adopting a narrowing construction of the statute, the Supreme Judicial Court rejected the contention that § 8 is overbroad. It also found no merit in Ps' vagueness argument because the specific prohibition against corporate expenditures on a referendum solely concerning individual taxation is 'both precise and definite.' Finally, the court held that Ps were not denied the equal protection of the laws. The court held that corporate speech is protected by the First Amendment only when it pertains directly to the corporation's business interests.