SACRAMENTO — A surge in enthusiasm among Latino voters between Labor Day and Election Day led to a record-breaking turnout largely responsible for Gov.-elect Jerry Brown’s decisive victory.

That was the assessment offered Thursday by David Binder, a pollster who worked with labor groups that put together a $25 million, coordinated, independent expenditure campaign in support of Brown.

Binder said polling he conducted Sept. 1 placed the enthusiasm level of Latino voters at 69 percent on his scale of 100. By Election Day, that number had climbed to 83 percent, a finding confirmed by actual turnout.

“We found that 22 percent of the electorate was Latino, a new high,” Binder said.

The surge in interest corresponded with a decisive shift in opinion among Latino voters, he said. His polling on Labor Day showed Latinos supporting Brown over Republican a.inline_topic:hover { background-color: rgb(234, 234, 234); } Meg Whitman by 14 percentage points, but by Election Day that lead had ballooned to 34 points.

“Latino voters came out in droves,” said Mike Garcia, president of the Service Employees International Union, United Service Workers West. “Those of us who were working at the polls saw huge numbers of Latinos standing in line, waiting to vote in that last hour.”

Both spoke at a post-election debriefing Thursday for reporters at which several of the state’s top union officials detailed their campaign activities. Art Pulaski, executive secretary-treasurer of the California Labor Federation, AFL-CIO, called it a campaign of “unparalleled intensity and unparalleled cooperation among unions.”

At a separate post-election seminar Thursday in Sacramento, Republican analyst Tony Quinn said the Democrats’ success — they swept all of the statewide contests that have been decided thus far and gained a seat in the Legislature — was because of Latino turnout.

The 2010 election, Quinn said, “finally proves that we no longer have a two-party system in California.”

Republican strategist Sal Russo, founder of the Tea Party Express that helped mobilize tea party activists in a number of campaigns in other states, called Quinn’s assessment too harsh but acknowledged California Republicans suffer from a lack of leadership.

“Parties are defined by their leaders,” Russo said. “And who do we have in California? There was George W. Bush, who wasn’t well-liked at the end, and Arnold Schwarzenegger, who has blurred the lines.”

Russo blamed much of the decline of the state Republican Party on the national strategy developed by Bush political adviser Karl Rove. That strategy, designed solely to ensure a Bush victory in enough states to win the presidency, was far too socially conservative for California, he said.

“Californians ask, what are Republicans? Well, they don’t like gay marriage and they pray a lot.”

Russo said Whitman “had the opportunity to redefine the Republican Party” in the state but failed because of a badly flawed campaign.

Labor officials said the governor’s race, the contest that drove all results further down the ticket, was very much up for grabs earlier in the year. Their polling showed Whitman leading Brown by 3 percentage points in March, nearly identical to the 4-point lead Schwarzenegger held in spring polling four years earlier.

The labor officials said they were determined not to allow a repeat of 2006, when Schwarzenegger advertised heavily over the summer at a time when Democrat Phil Angelides had no resources to answer back.

“We were very determined that was not going to happen again,” said Pulaski, who noted many of the state’s leading unions started saving money for the 2010 campaign immediately after Schwarzenegger’s victory four years ago.

Lou Paulson, president of the California Professional Firefighters, said independent expenditure campaigns spent $8 million over the summer on television and Internet advertising. Although Whitman spent $24 million over the same period, he said, the labor-funded campaign over the summer was enough to help keep the race even until Brown launched his own campaign on Labor Day weekend.

Garcia described a $5 million independent Spanish-language campaign featuring television, radio advertising, direct mail and person-to-person contacts as the largest campaign targeted at Latino voters in American political history.

It was launched partly in response to aggressive Spanish-language advertising Whitman began airing immediately after winning the GOP primary in June.

Garcia said the SEIU campaign, citing Whitman’s positions on immigration and college access for immigrant students, asserted that what the Republican candidate “was saying in English was a lot different from what she was saying in Spanish.”

“At the end of the day,” he said, “Latinos could not be bought.”

National Latino groups, citing polling in eight states, said Latino voters also were largely responsible for Democratic U.S. Senate victories in Colorado, Nevada and California.