New Jersey Democratic gubernatorial candidate Barbara Buono shouldn't let her supporters squash a bill that would force secretive advocacy groups to disclose their donors. Sitting on legislation that would give New Jersey voters a hint of who is trying to influence the race for governor is as hypocritical as it should be embarrassing for the Middlesex County state senator. She sponsored a similar bill that died for lack of support last year.

So-called issue-advocacy or dark-money groups are organized under a section of the tax code that allows them to conceal their donors. That means no one has to take public responsibility for their advertising, which is often negative and even more misleading than the candidates' ads. Corporations and wealthy individuals can hide behind the groups to avoid alienating customers, associates, and stockholders who might object to the messages.

Political candidates and parties have to disclose their donors and take the heat for any deceptive ads they place. But these shadow groups force voters to evaluate campaign advertising without knowing who is behind it. And they spent billions to influence last year's presidential election.

This year, only New Jersey and Virginia are holding gubernatorial races. These off-year elections will be seen as bellwethers of the following year's midterm congressional results. That makes them attractive to donors who want to secretly bet on one party or the other, especially given the national popularity of Buono's opponent, Gov. Christie. The group One New Jersey has already aired ads critical of Christie.

The bill to require disclosure of such groups' donors was taken off the voting list by Buono's supporters in the Assembly last week, according to the Star-Ledger. They may have been reacting to the Democrat's abysmal fund-raising: Her campaign has raised less than $750,000, while Christie's has raised more than $5 million. But protecting shadow advocacy groups is not the right way to even the financial playing field.

If Buono's campaign abandons the candidate's principles in the hope that some secretive group might support it, what will it tell voters about her and her party? The candidate can say that her supporters are operating without her knowledge or direction, and that may be true. But now she knows better, and she must call for the bill to be put to a vote.