The indictment last month of seven current and former executives of one of the state's biggest engineering firms revealed a gaping hole in New Jersey's campaign-finance laws.

The executives of Birdsall Services Group were charged with money-laundering, conspiracy and making false representations for government contracts. The state alleges that Birdsall solicited contributions of $300 from its employees, reimbursed them with bonuses, and bundled the donations to give Democratic and Republican candidates $686,000 over a period of six years.

Under the state's pay-to-play law, those donations should have disqualified Birdsall from obtaining government contracts, but the firm has received $86.7 million in such contracts since 2008 - $28 million worth of contracts in 2011 alone.

So why did Birdsall allegedly solicit donations of $300 or less? Because that is the threshold for reporting the identity of campaign donors in New Jersey. The politicians who cashed all those bundled checks did not have to tell anyone whom they were from.

In most other states, campaigns must report the identity of donors who give as little as $100 or $50. The Star-Ledger reported Sunday that the higher limit means New Jersey politicians can keep more of their donors secret than in any other state. In 2011, of a total $100 million in political contributions statewide, no donor information was given for $12 million. So 12 percent of New Jersey donations were kept secret.

Jeffrey Brindle, executive director of the Election Law Enforcement Commission, told The Star-Ledger his office will consider recommending a lower reporting threshold for New Jersey to bring it in line with other states.

But the real question is, why have any limit at all? A half dozen states, including Florida, Ohio and Maryland, require disclosure of all campaign donations, regardless of amount.

And if any state needs that kind of transparency, it's New Jersey, where political sleight of hand has long been a favorite sport. If companies are adept at bundling $300 donations - and you can bet this practice goes well beyond a single engineering firm - they could certainly do the same thing with $100 donations.

The $300 threshold was originally intended to cut down on paperwork that campaigns file with the state. But since most campaigns and political organizations keep records on computers now, filing reports is easier. It is no hardship to have them report everything, and no hardship for the state to keep those records.

Would full disclosure inhibit some small donors who value their privacy from contributing to a campaign? Perhaps. But why shouldn't voters at every level know who is writing checks to their public officials, and to whom those officials are indebted?