In a 5-4 decision written by Chief Justice John Roberts, the Supreme Court today struck down Arizona's controversial campaign finance law which allowed publicly-funded candidates to receive "equalizing" public money designed to match the expenditures of privately-funded candidates. In essence, once a certain expenditure threshold was reached, every additional dollar that a privately-funded candidate spent was matched by a public dollar that went to his or her publicly-funded opponent. As Chief Justice Roberts held, this "scheme substantially burdens protected political speech without serving a compelling state interest and therefore violates the First Amendment." Here's more from the majority opinion delivered today:

Once a privately financed candidate has raised or spent more than the State's initial grant to a publicly financed candidate, each personal dollar spent by the privately financed candidate results in an award of almost one additional dollar to his opponent. That plainly forces the privately financed candidate to "shoulder a special and potentially significant burden" when choosing to exercise his First Amendment right to spend funds on behalf of his candidacy.

Roberts also addressed the argument that the matching funds law resulted in more political speech, not less, and therefore deserved judicial protection: