The California Teachers Association spent $211.8 million - more than any other special interest group - over the past decade to influence state voters and politicians, according to a state report released Wednesday.

Three Indian tribes dumped another $200 million into the political process and big business shelled out more than $500 million, the California Fair Political Practices Commission said in its report, "Big Money Talks."

"The reality in politics is that money talks. Sometimes money shouts," the report says. "If it didn't, special interests simply would not spend so much money trying to influence public policy and elections. ... This report leaves little doubt where the vortex of power lies in this state."

In all, 15 groups - two labor unions, six corporations, three Indian tribes and four business associations - spent more than $1 billion over the past 10 years to sway the outcomes of elections and government decisions, the report said.

These labor unions, Indian tribes and drug, utility, oil, telecommunication and tobacco companies "have a disproportionate amount of influence on California elections and public policy," the FPPC concludes.

The report warns that there is "no end in sight to the spending binge," noting that more than half of the money - nearly $660 million- was spent on state and local ballot measures. Often, the report says, the top-spending 15 special interest groups "win by spending money to defeat ballot measures" to maintain the status quo.

For example, the California Teachers Association, which represents 330,000 public school teachers in the state, spent $26 million to defeat a school voucher system in 2000 and another $50 million to kill three other ballot measures. The Pharmaceutical Research and Manufacturers of America, which represents pharmaceutical research and biotechnology companies, shelled out a whopping $95 million to defeat two dueling initiatives on a 2005 ballot aimed at establishing prescription drug discount programs for low-income Californians. Both measures lost.

CTA President David Sanchez said the group is simply doing what its members expect: advocating for public education. He said the process is working, and argued that voters agreed in 2005, when they defeated a ballot measure that would have prohibited the use of union dues for political contributions.

"One of the reasons I joined the union was to ensure that there was a voice willing to advocate on our behalf and on behalf of students," he said. "We are the only advocates for our issues."

While the powerful teachers union topped the spending list and the California State Council of Service Employees - which lobbies on behalf of public employees represented by SEIU labor chapters - came in second, at $107 million, business wasn't far behind. Six corporations funneled nearly $324 million into the political process, including $69.2 million spent by Pacific Gas & Electric Co., $66.2 million by Chevron Corp. and $59.6 million by AT&T Inc.

Daniel Newman, executive director of Maplight.org, a nonpartisan nonprofit in Berkeley that tracks the impact of money on politics, said the report shows that Californians are electing the best fundraisers, not the best leaders.

"When unions and corporations are paying for politicians to get power and stay in power, that's corruption," he said. Lawmakers, Newman added, "are working for two masters - the donor and the voter. And after they are elected, we know who has the upper hand."

Newman's organization released its own report Wednesday showing how CTA contributed two to three times the amount of money to the campaigns of legislators who later voted against a package of education bills the union opposed.

He said publicly funded elections are the best way to avoid this "corruption," and noted that a pilot program, Prop. 15 - which would charge lobbyists fees and use the money to fund secretary of state candidates - will appear on the June ballot.