With his libel-slander lawsuit, Ben Cayetano is calling out the cabal that has shamelessly tried to cast him as a crook. He’s saying he’s not going to take the slurs anymore.

He should not have to, but whether he can win in court is another matter. It is a challenging case, given his long career in public office, but if anyone has the will to stop or slow the relentless proliferation of dirty tricks in island campaigns, Cayetano does.

Pacific Resource Partnership and its allies, the targets of the suit, have relentlessly and falsely accused him of taking bribes when he was governor in its effort to run his candidacy for Honolulu mayor into the ground and elevate the city rail project he opposes. PRP and its brigade have millions of dollars to gain in building the ill-conceived rail line that will tax the city’s finances, and their fetid offensive to nail him comes with the blessing of the U.S. Supreme Court.

The anti-Cayetano scheme is Hawaii’s addition to the toxic national political pollution that the court’s 2010 ruling has bred. The infamous “corporations are people” decision allowed unlimited spending by groups to support or oppose candidates and public policies without having to disclose who is behind the money.

Jim Bickerton, one of Cayetano’s lawyers, describes the libel case as one “about big money for big lies.”

“It’s about whether we’re going to let secret, shadowy groups with unlimited funds pump lies into the public discourse,” he said.

The ruling, Citizens United v. Federal Election Commission, was seen as an advantage to Republicans who were largely favored by the wealthy-Wall Street-corporate world. They did not expect that Democratic organizations, who were not as well financed, would use their money tactically to target GOP candidates for the U.S. House and Senate as well as state and local offices.

Feeling the breath of challengers on the back of their Republican necks, influential members of Congress are finally acknowledging the consequences of Citizens United and considering reform. But this may all be pre-election jitters. Depending on the outcome of the elections, legislative curbs may not materialize.

Because of Citizens United, no person or entity has to tie their names to the ugly. Cayetano’s lawsuit pulls away part of PRP’s veil, naming the trustees of the Hawaii Carpenters Union, and its PR firm’s principals. It also hopes to later identify an unknown number of behind-the-scenes individuals who are believed to have taken part in the vicious campaign.

One person who has stood clear of the muck is Cayetano’s rival, Kirk Caldwell. To his credit, the former city managing director under Mayor Mufi Hannemann has not followed PRP’s lead. Caldwell this week would not discuss the suit, saying the law that disallows candidates from coordinating campaigns with PACs prevents him from speaking to PRP. The law, however, doesn’t prevent him from censuring PRP’s unethical behavior from which he will benefit.

Watching from the sidelines while his opponent is maligned is cheap.