California’s population would have dropped over the past two decades were it not for a huge increase in Hispanics and Asians, 2010 census figures released Tuesday show.

The trend is the same in Orange County as it is for the state: Whites have been decreasing in large numbers since 1990, while Hispanics and Asians increased. The shifting demographics have helped Anaheim pass Santa Ana as the county’s biggest city, with Irvine now a distant third.

The census, completed last year, bears the scars of the national recession – from the number of homes found vacant here to the explosive growth of the less-expensive Inland Empire. It shows that Orange County grew by about 6 percent in the past decade and is now the third most populous county in California, after Los Angeles and San Diego, with a little more than 3 million people.

“We’ve never had a census like this before, during a recession,” said Dowell Myers of USC’s School of Policy, Planning and Development. “That kind of distorts a lot of things.”

More than 2 million whites have left California – or died – since 1990, the census numbers show. At the same time, though, more than 6 million Hispanics and 2 million Asians moved here or were born here – accounting for almost all of the state’s growth over the past two decades.

Without that growth, the state would have lost federal tax dollars, which are often awarded according to census population counts. It could also have lost political clout in Washington, because Congressional districts are determined by the census.

The only thing different in Orange County was the size of the numbers. The county lost about 15 percent of its white population (about 226,000 people) but gained nearly 80 percent more Hispanics (nearly 450,000 people) and more than 120 percent more Asians (more than 290,000 people) since 1990, according to the census. Click here to see an interactive map of the changes in every California county.

Those changes reshuffled the hierarchy of Orange County cities. Anaheim lost more than 20 percent of its white population between 2000 and 2010 but nonetheless emerged as the county’s biggest city thanks to increases in its Hispanic and Asian populations.

Anaheim unseated Santa Ana, the county’s longtime big-city title holder, which lost whites in big numbers but also lost about 1 percent of its Hispanic population. Santa Ana Mayor Miguel Pulido said he believes there was a miscount, and plans to challenge the numbers.

Irvine gained thousands of white and Hispanic residents, the census showed, but it was the Asian population that pushed it into third place among Orange County cities. That population nearly doubled between 2000 and 2010, to nearly 83,000 in a city of about 212,000.

The increase in the Asian population countywide came as no surprise to Janet Nguyen, who was elected the first Asian-American supervisor in Orange County in 2007. She attributed the rise to the second generation of immigrants who have settled here. Now young adults, they’re getting married and having children, she said.

“California is kind of the picture of where the nation is going in the next couple of decades,” said Steven Ochoa, the national redistricting coordinator for the Mexican American Legal Defense and Education Fund. “We are a multi-cultural society; we have a great mix of human beings in this state.”

But experts were surprised at the decline in the white population, said USC’s Myers. He attributed the losses to high unemployment among young adults, who were forced to move out of state to find a job.

But he also speculated that a conservative backlash against the government may have driven down the numbers. He pointed to talk among white conservatives about invasion of privacy and refusal to participate in the census to protest government intrusion. We may be seeing “a new politically induced undercount,” he said.

What’s certain, though, is that the 2010 census captured a snapshot of America still reeling from the recession. In Orange County alone, it found more than 56,000 vacant housing units – about 5.5 percent of the county’s housing stock. In 2000, the number was closer to 3.5 percent.

It also showed a map-changing wave of migration into the Inland Empire, where housing prices were less expensive. While Orange County grew by about 6 percent; Riverside County grew by nearly 42 percent.

That will cause ripples well into the next decade, said Nancy D. Sidhu, the chief economist of the Los Angeles Economic Development Corporation. She doesn’t expect the housing bust to end the Inland Empire boom, and that will affect Orange County for years to come.

If nothing else, she said, traffic on the 91 freeway could be “potentially more difficult 10 years from now than it is today.”

Register Staff Writer Andrew Galvin contributed to this story.

Contact the writer: 714-796-5030 or rcampbell@ocregister.com