In a burst of judicial activism, the Supreme Court on Tuesday upended the gubernatorial race in Arizona, cutting off matching funds to candidates participating in the state’s public campaign finance system. Suddenly, three candidates, including Gov. Jan Brewer, can no longer receive public funds they had counted on to run against a free-spending wealthy opponent.

The court’s reckless order muscling into the race was terse and did not say whether there were any dissents, though it is hard to imagine there were not. An opinion explaining its reasoning will have to wait until the next term, assuming it takes the case, but by that time the state’s general election will be over and its model campaign finance system substantially demolished.

It seems likely that the Roberts court will use this case to continue its destruction of the laws and systems set up in recent decades to reduce the influence of big money in politics. By the time it is finished, millionaires and corporations will have regained an enormous voice in American politics, at the expense of candidates who have to raise money the old-fashioned way and, ultimately, at the expense of voters.

Arizona’s clean elections program was established by the state’s voters in 1998 after a series of scandals provided clear illustrations of money’s corrupting influence. In particular, the program was prompted by the AzScam scandal of 1991, in which many state legislators were recorded accepting contributions and bribes in exchange for approval of gambling legislation.