The law was passed after a public corruption scandal and was intended to reward candidates who forgo raising their own campaign cash, even in the face of heavy spending by opponents with private money.
Those who challenged the Arizona law said it caused them to rein in spending to prevent their political opponents from getting a fresh infusion of state money.
The court said the trigger violates the First Amendment but left in place the rest of Arizona’s public financing system.
“Laws like Arizona’s matching funds provision that inhibit robust and wide-open political debate without sufficient justification cannot stand,’’ Roberts said.
At least four other states, Maine, New Mexico, North Carolina, and Wisconsin, have similar trigger provisions that affect some political races, and they could be vulnerable.
Senate Republican leader Mitch McConnell of Kentucky praised the decision. “The Supreme Court ruled that a state cannot use taxpayer funds to punish a successful political campaign,’’ McConnell said.
William Maurer, an attorney with the Institute for Justice representing the challengers, said the court reaffirmed its opposition to campaign spending laws that seek to level the playing field.
But Justice Elena Kagan said in dissent that the law was a reasonable response to political scandal. Reading a dissent aloud for the first time since joining the court last year, Kagan said that by providing candidates with additional money, the law actually provided for more, not less, political speech.
Arizonans “passed a law designed to sever political candidates’ dependence on large contributors,’’ Kagan said. “It put into effect a public financing system that attracted large numbers of candidates at a sustainable cost to the state’s taxpayers.’’
Justices Stephen Breyer, Ruth Bader Ginsburg, and Sonia Sotomayor signed onto Kagan’s dissent.
