Few political groups have been as successful in recent years at shaping state policies as the Humane Society of the United States under Wayne Pacelle.

Now that the nation's largest animal rights group has effectively banned the caging of egg-laying hens in California, it is turning its focus to Washington.

A week after voters here overwhelmingly approved Proposition 2, Pacelle called on the Humane Society's 10 million-plus members "to build on the momentum of that landmark outcome."

In e-mails, the group's executive director urged "friends" to send a message to President-elect Barack Obama urging him to "consider animal protection a priority when appointing his secretary of agriculture."

Past secretaries, he said, have been "too closely aligned with industry, and now it is time to appoint a secretary who balances economic concerns with animal welfare, consumer safety, and environmental protection."

Since taking over the nation's largest animal advocacy group four years ago after a decade as its chief spokesman and director of government affairs, Pacelle – a glib, photogenic vegan – has continued the organization's transformation.

No longer does it just look out for dogs and cats; it's a political power whose clout Pacelle believes one day will rival the National Rifle Association.

"We have the potential to be one of the most powerful forces in politics," Pacelle says.

In 2008, the Humane Society shepherded through 88 new state animal welfare laws and capped off the year with its crowning achievement, Proposition 2.

Under Pacelle, the Humane Society has stepped up its fundraising and doubled its assets to nearly $225 million.

But critics accuse the organization, which turns to voters when it is defeated by farmers in state legislatures, of advancing a radical agenda at the polls.

"They're seeing more success with ballot measures than legislatively," said Julie Buckner, a spokeswoman for the No on Proposition 2 campaign, which was funded by egg producers. "The ag industry has some clout, but not necessarily with voters."

Pacelle – who is compensated with a $207,000 annual salary and a generous benefits package – counters that the Humane Society is merely exercising the "mainstream ethos" of its members, who live in every community in the nation.

"We're not telling people to become vegetarians – we're urging them to exhibit greater decency," he said.

In February, a hidden-camera video recorded by the group showed cows being abused at a San Bernardino County slaughterhouse and led to the largest meat recall by federal officials in history.

But it is at the ballot box that the Humane Society has made its most sweeping mark, aided by an army of committed volunteers.

Since 1990, when the organization worked on a ballot measure that banned the hunting of mountain lions for sport in California, it has taken on more than two dozen statewide measures and amassed an enviable record.

"We've had the highest rate of success of any kind of cause or constituency, winning about 75 percent for all the ballot measures we've run," Pacelle said.

By comparison, between 1940 and 1990, animal rights advocates were involved in only about a half dozen ballot measures and prevailed in only one campaign.

"The conventional wisdom coming into the 1990s was that opponents had too much money and resources, and they could confuse and push people to vote for them," Pacelle said.

After the mountain lion measure passed in California, the Humane Society began running ballot measures throughout the nation.

Its victories have included bans on hunting bears with bait in Colorado, Oregon and Washington; same-day airborne hunting of wolves and foxes in Alaska; and cockfighting in Arizona, Missouri and Oklahoma.

In a match pitting political titans, the Humane Society beat the National Rifle Association in Michigan, where it banned the hunting of mourning doves.

Measures the group has run in California have banned the use of indiscriminate traps and poisons as well as the slaughter of horses and sale of horse meat for human consumption.

After banning the use of gestation crates and veal crates for livestock in Arizona in 2006, the Humane Society this year turned its attention to California.

When Proposition 2 takes effect in 2015, it will prohibit farmers from confining egg-laying hens, gestating pigs and calves in cages that severely restrict their normal movements.

There is little veal production in California, and farmers have voluntarily phased out confining sows in breeding crates, so the measure will apply primarily to egg-laying hens.

Farmers predict the cost of the new law will drive egg production out of the state – an argument Pacelle doesn't buy.

Moreover, he believes the federal government should follow California's lead.

With oversight of the federal Animal Welfare Act and the Humane Methods of Slaughter Act, Pacelle believes the next agriculture secretary can have a big impact.

"The federal government can stipulate that animals raised for food cannot be confined for the entirety of their lives in tight cages," he said, noting European Union nations are phasing out the practice.

Obama has not indicated who will run the Department of Agriculture. But among the names that have been mentioned are former Iowa Gov. Tom Vilsack; Tom Buis, president of National Farmers Union; and John Boyd Jr., president of National Black Farmers Association.

Tracy Grondine, a spokeswoman for the American Farm Bureau, said it would be "too short-sighted to pick someone based on one issue such as animal rights."

"The ag secretary has many things under his or her purview," she said. "I think it's important to have industry knowledge as well."

Call Aurelio Rojas, Bee Capitol Bureau, (916) 326-5545.