SACRAMENTO — Hamstrung by strict limits on political contributions, California lawmakers have found a way to continue to extract large sums from some of Sacramento’s most powerful special interests.

Increasingly, they’re using “ballot measure committees,” little-known and barely regulated accounts that are supposed to promote or oppose state and local initiatives, but in practice are paying for consultants and polling firms, new suits and trips to Mexico. And the money for the politicians’ perks comes in the form of five-figure donations from the same special interests that state rules were intended to curtail.

A Bay Area News Group analysis shows that the number of candidate-controlled ballot measure committees has skyrocketed from six to at least three dozen over the past decade. Of the nearly $3 million spent by these committees since 2013, only $1 out of every $4 was used to help pass or kill measures that actually made it to the ballot.

Under the vague language of a 47-year-old political law, elected officials can legally operate these committees — but the way they’re doing it appears to bend state laws and rules governing how the money may be spent. And no state agency adequately monitors the situation.

“Candidates are increasingly using these committees as slush funds for unlimited contributions from special interests,” said Kathay Feng, executive director of California Common Cause, a leading good-government advocacy group, when told of the newspaper’s analysis. “They’re paying off lawmakers without technically violating the law. It’s disgusting.”

Indeed, much of the spending has become a way to cozy up to the special interests whose money fuels Sacramento politics. One former Fresno assemblyman used $25,000 from his ballot measure committee to buy custom suits for his donors. A Los Angeles lawmaker spent $17,000 on appetizers for his benefactors. Another Southern California lawmaker flew donors to Guadalupe, Mexico, for a fundraising bash.

In all, 32 legislators, including both Democratic legislative leaders, control ballot measure committees, along with four state constitutional officers. Belying the reason for their existence, 25 of the lawmakers’ committees have never reported contributing to a ballot measure campaign. And of those that have cut checks to help support or oppose a ballot initiative, many used the money for pricey television ads starring the lawmakers as they ran for re-election.

Feng said the reason the committees have become so popular in recent years is that donors who wish to support a state lawmaker’s campaign must abide by strict contribution limits that voters imposed at the ballot box in 2000 when they passed Proposition 34. Those rules don’t apply to candidate-controlled ballot measure committees.

As a result, lawmakers may deposit unlimited sums of money from Big Oil, unions and other special interests into these accounts. This news organization’s analysis found that more than half of all the checks the committees have cashed since 2013 exceeded the $4,200 limit on donations to individual lawmakers’ re-election committees — and half of those gifts were worth tens of thousands of dollars each.

Former Assembly Speaker Toni Atkins’ committee received $90,000 in contributions from AFSCME, a union of state, county and municipal workers. Assemblyman Marc Levine, a San Rafael Democrat and champion of charter schools, received four $50,000 checks from John and Regina Scully, a wealthy Mill Valley couple who have spent millions to promote charters.

Levine was among the 19 legislators with ballot measure committees who either declined to speak about their committees or did not return repeated calls and emails seeking comment.

Many of the legislators who did answer questions from this news organization disputed the need for tighter regulation of candidate-controlled ballot measure committees. “The right of officeholders to engage in these far-reaching policy debates shouldn’t be limited just because they happen to be elected to something,” said Jason Kinney, a spokesman for Senate President Pro Tem Kevin de León, noting that special interests can spend unlimited sums on ballot measures they tout. Kinney said de León keeps a “firewall” between his fundraising activity and his duties as a public servant.

That may be, but the committee accounts are flush with donations from the beneficiaries of lawmakers’ votes.

In December, Assemblyman Adam Gray’s committee took a $25,000 check from the California Independent Petroleum Association, bringing his total to $50,000 from the oil and gas industry trade group. That was three months after the Merced Democrat, a member of a powerful bloc of pro-business Democrats, helped the industry kill efforts to require California to cut petroleum use by motor vehicles 50 percent by 2030.

In 2013, Sen. Ed Hernandez, D-West Covina, authored legislation that would have allowed optometrists to provide basic medical care to Medi-Cal patients. The unsuccessful measure would have been a windfall for the industry. Since then, the California Optometric PAC has given his ballot measure committee $130,000.

Gray and Hernandez were two of the other legislators who refused to answer questions from this newspaper about their use of ballot measure funds.

While there may be no direct evidence of corruption from such fundraising, it still looks “pretty bad,” said Thad Kousser, a political scientist at UC San Diego. “Why are these interest groups giving them this money? Is it because they support a particular ballot measure, or because they have a bill before the Legislature?”

Initiative sponsors — many of them politicians — have been using committees to raise money to advance their causes since Gov. Hiram Johnson brought direct democracy to California in the early 20th century, but the modern era for ballot measure committees didn’t begin until after 1981, when the U.S. Supreme Court ruled in Citizens Against Rent Control v. City of Berkeley that while restrictions on donations to candidates are OK, limiting the money that goes to initiative campaigns would violate the First Amendment.

The court’s thinking: Limits on candidate fundraising could be justified by the need to prevent political corruption, but the same logic didn’t apply to ballot accounts because when the beneficiary was a cause rather than a person, there was no one for deep-pocketed donors to corrupt.

Campaign finance experts say the justices’ rationale quickly became outdated as politicians rushed to set up ballot measure committees to collect unregulated dollars and use them for their own purposes.

“It strains common sense to think that candidates aren’t thankful for contributions made to committees they control,” said Jessica Levinson, a campaign finance expert at Loyola Law School. “They’re using these committees to legally exploit the law.”

California’s Fair Political Practices Commission agreed there was a problem, and in 2004 it tried to impose restrictions on candidates’ ballot measure fundraising. Former Gov. Arnold Schwarzenegger, who had turned to the ballot to advance policy measures he couldn’t pass in the Legislature, challenged the regulations in court. A Sacramento County Superior Court judge struck down the FPPC’s rules the following year, and since then the state’s political watchdog has been mostly muzzled.

Under FPPC rules adopted in 2009, the agency does not even require candidates to disclose the names of ballot measures they support or oppose in public records, unless they spend more than $50,000 on the effort. And they need not list the names of the initiatives they’re working on when they spend committee money on items such as fundraising, travel and attorney’s fees.

Asked why the FPPC hasn’t done more to address the problem, spokesman Jay Wirenga blamed the Schwarzenegger lawsuit. “Re-litigating a losing court battle would not be the best use of the commission’s limited resources,” he said. He also said the commission doesn’t have the wherewithal to track the committees’ spending and fundraising to make sure it is truly being done on behalf of ballot measures, and he called on the Legislature to give the agency the authority to do more.

But Dan Schnur, a former FPPC chairman who is now director of the Jesse M. Unruh Institute of Politics at the University of Southern California, said any suggestion that reform will come out of the Capitol is ludicrous.

“Asking legislators to reform their own fundraising practices is like asking teenagers to set their own curfew,” Schnur said.

Sen. Lois Wolk, D-Davis, did carry legislation more than a decade ago when she was an Assembly member that sought to close the loophole, but the measure failed.

Democratic Party leaders had pitched the accounts to her as “a good way to raise money,” once urging Wolk to open a committee herself, she said. “But I said no, no, no, no, no, no.”

Schwarzenegger, at least, was very publicly using his ballot measure committees to seek support for his agenda. These days, many politicians use their committees for purposes that remain obscure, at least as far as their public disclosures go.

Of the 32 lawmakers who have active ballot measure committees and served during the current legislative session, only seven have spent any money since 2013 on measures that made it to the ballot, the Bay Area News Group found — despite FPPC rules that say the committees are limited to “activities related to a state or local ballot measure or potential measure.”

The rest tend to describe the purpose of their committees on required campaign finance forms in general terms, such as “to support or oppose state and local ballot measures” they never name. Sen. Isadore Hall, D-Compton, outlined his committee’s purpose with even less clarity, stating that it was organized for “exploration issues related to the budget, not a ballot measure yet.”

Not knowing which causes they were supporting wasn’t a stumbling block for half a dozen top donors who since 2013 have each given more than $100,000 to lawmakers’ ballot measure committees. They include health insurer Blue Shield; the Temecula-based Pechanga Indians; AFSCME, the public employees union; and a trade group representing construction workers.

The four lawmakers who have collected the most money are Atkins, D-San Diego; Gray, chairman of the Assembly Governmental Organization Committee; Hernandez, chairman of the Senate Health Committee; and Senate leader de León, D-Los Angeles. Donations to their committees total $2 million — more than half the money raised by all the committees since 2013.

Over the last two years, Hernandez has spent more than $50,000 in ballot measure committee money hosting fundraisers at Las Vegas casinos — but in the eight years he has had his committee he’s never reported spending money on a measure that reached the ballot.

Former Assemblyman Henry Perea, D-Fresno, has spent money on ballot measure ads that featured him. But he also invited his donors to R. Douglas Custom Clothier in Sacramento, where he spent $25,000 of his ballot measure funds having custom suits made for them.

Perea, who quit the Legislature last December to take a job as a pharmaceutical industry adviser, declined to comment.

Asked by a reporter which cause Los Angeles Assemblyman Sebastian Ridley-Thomas had gathered donors for in December when he spent $17,000 on appetizers at STK, a chic Los Angeles steakhouse frequented by celebrities, his representative refused to say.

“If I wanted to get grilled on an individual expense, I wouldn’t have returned your call at all,” spokesman Phil Giarrizzo said. “I don’t see anything unusual about having to spend money to raise money.”

Sen. Cathleen Galgiani, D-Stockton, acknowledged in an interview that she used more than $200,000 raised by her ballot measure committee to pay for attorneys who did work completely unrelated to ballot measures. She insisted she did nothing wrong, saying the issues the attorneys handled — including a controversy over missing-person files that had been improperly deleted by the San Joaquin County Sheriff’s Office — were top priorities for her constituents and “the state can’t take that on.”

In none of these cases has the FPPC challenged the lawmakers’ uses of the ballot measure money. Nor has it done so when a committee’s activities are clearly intended to bolster a lawmaker’s own career. Gray’s 2014 advertisement for Gov. Jerry Brown’s ballot proposals for a $7.5 billion water bond and beefed-up rainy day fund, for instance, not only starred him but also included a graphic that mentioned his campaign for re-election.

A bill authored this year by state Sen. Pat Bates, a Republican from Laguna Niguel, would have barred candidates and elected officials from using money raised by candidate-controlled ballot measure committees to promote themselves, their candidacies or the campaigns of others.

That bill died quietly in the Senate Appropriations Committee in May without any explanation from the Democratic members about why they refused to support it. All but three of the legislators who now have ballot measure committees are Democrats.

The lack of transparency is unacceptable, Bates said.

“We need to give the public a reason to have faith in government and believe that politicians are not bought and paid for,” she said. “We’re testing their faith in government when we refuse to close loopholes like this one.”

Contact Jessica Calefati at 916-441-2101. Follow her at Twitter.com/Calefati.