If there’s one main reason for the distrust many Californians feel for government and elected officials at all levels, it may be the way special interests from corporations to labor unions to individual billionaires pour millions of dollars into elections campaigns while hiding their identities.

Almost five years ago, Julia Brownley, then an obscure assemblywoman and now a Democratic congresswoman from Ventura County, began trying to get state legislators to fix a bit of that.

Under the U.S. Supreme Court’s infamous best replica watches Citizens United decision, it’s impossible to stop these groups from pouring as much money as they like into campaigns, both for individuals and initiatives. But there are ways to force disclosure of their identities even when they’d like to remain anonymous.

So Brownley sponsored something backers called the “Disclose Act,” aiming to force disclosure of the sources for all significant campaign donations. The reasoning was that if voters knew, for instance, that Chevron Corp. was the leading donor to the “no” side of an initiative campaign about putting a tax on oil drilling, they might be a bit more skeptical of whatever arguments are made in TV commercials.

As it stands, companies like Chevron, Exxon, Tesoro and Valero can create and donate to campaign committees with benign names like Californians Against New Taxes without much muss or fuss.

The Disclose Act would require such committees to reveal the three leading donors behind each political newspaper, TV or radio ad, lifting the fig leaf that has long obscured who’s doing what. It would also compel nonprofits funneling money into campaigns from anonymous donors to reveal their identities.

But it failed in 2011, and Brownley went on to Congress, where she’s in her second term. That left backers to find new sponsors for the Disclose Act and they’ve done so each year since.

Meanwhile, bit by bit, the ideas in the Disclose Act are moving toward reality. The first movement came with a 2014 state Senate bill known as SB27, which passed in part because of outrage over an out-of-state non-profit dumping $11 million into California campaigns at the last moment before the November 2012 election. Even though the state Fair Political Practices Commission fined that Arizona-based outfit $1 million, it wasn’t forced to disclose names, even after the election.

In response, almost two years later, Gov. Jerry Brown signed SB27, forcing non-profits to disclose the sources of their so-called “Dark Money” on the secretary of state’s website.

That’s a help, but it’s not enough. Most voters will never take the trouble to look on that website for the information. A more direct approach is needed.

Enter this year’s version of the Disclose Act, known as AB700 and sponsored by Democratic Assemblymen Marc Levine of San Rafael and Jimmy Gomez of northeast Los Angeles. This bill would compel political ads to disclose their top three funders clearly and unambiguously in the ads. The funders disclosed must be the original ones, not dummy committees like those used in the past to mask their activity by interests from labor unions to tobacco, chemical and oil companies, not to mention wealthy individuals.

The disclosure would have to come in large letters at the beginning of TV ads, not in fine print at the close, where no one is likely to notice. That way, voters would know who is behind a message while they’re seeing and hearing it.

This isn’t quite as radical an idea as one that surfaced in a 1990s-era initiative that would have required similar disclosure in type matching the largest and most colorful contained in any ad or commercial.

Maybe that’s why the Assembly Election Committee passed it last month on a 4-2 vote.

That vote meant the idea of disclosing top donors prominently has already gotten farther toward becoming law than ever before. It’s a tactic vitally needed in an era of unfettered spending by wealthy interests on all sides of the political spectrum. If spending can’t be limited, at least voters should know who’s doing it.

So bit by bit, key elements of the original Disclose Act may well become reality. And the more the better, hopefully in plenty of time for next year’s initiative-loaded elections.