Suddenly this fall, a threat has emerged to the vote-counting reliability Californians have enjoyed for the last six years.

This comes from a new law just signed without hoopla by Gov. Jerry Brown, who listed it among 30 signings and five vetoes in a routine press release.

Here’s the possible threat: This measure will allow the California secretary of state to approve new electronic voting systems that have received no certification at all for use in actual elections. It also ends a long-standing requirement that all electronic voting systems be certified at the federal level before they’re used here and allows counties to develop their own voting systems.

This bill cried out for a veto from Brown, considering the problems encountered by electronic voting systems during much of the last decade. Comprehensive testing demonstrated that many could be hacked, with the possibility that programming might be inserted so that — for one example — when a voter touched a screen favoring one candidate, the vote actually went into someone else’s column.

No one ever proved that such hacking occurred in a real election, but the machines’ hardware and software could make this kind of cheating virtually undetectable.

Some Democrats have long believed cheating of that kind occurred in Ohio in 2004. They note that the head of a firm called Diebold Election Systems co-chaired the Ohio campaign of Republican President George W. Bush and promised he would never allow 2004 Democratic challenger John Kerry to take that state.

Had Ohio gone for Kerry, he might have been president until early this year.

This background led current California Secretary of State Debra Bowen to center her 2006 election campaign around the issue of voting machine reliability. Immediately after her election, she conducted a “top-to-bottom” review of electronic voting here, with one result being that every electronic voting system used in this state has had to get both federal and state testing — until now.

Why tinker with voting machines now? Here’s what the new law’s legislative sponsor, Democratic state Sen. Alex Padilla of the San Fernando Valley, an MIT graduate and once the youngest president of the Los Angeles City Council, said in press releases as his measure easily wended its way through the Legislature:

“Most California counties purchase their voting systems from … private vendors. (This) has resulted in a patchwork of technologies throughout our state. The private vendors consider their technology proprietary …; Currently, state election officials and the public are completely dependent upon these vendors. … Allowing counties to develop, own and operate voting systems will increase voter confidence in the integrity of our elections.”

Padilla, who will be termed out of the Senate late next year, is a candidate for the Democratic nomination for secretary of state. If he wins the office, he would enjoy the new authority granted in his own bill.

His press releases never mentioned the fact that experimental systems will now be usable in pilot programs in real elections. Nor the fact that counties already can develop their own voting systems.

In other words, machines that might be as hackable as Diebold’s or even more corruptible may soon count the votes in some California elections.

This has the potential of opening a Pandora’s box filled with expensive recounts, legal challenges to election outcomes and deflated public confidence in the electoral process. That’s the very opposite of what Padilla’s press releases promised.

Which is why this measure is a prominent entry in the unofficial sweepstakes to determine this year’s worst new state law, one that should be viewed skeptically by Californians of every ideological stripe.

Thomas D. Elias is a writer in Southern California. tdelias@aol.com