FREMONT — The war of words between two East Bay groups on opposing sides of the immigration debate is escalating as their leaders this week traded barbs and accusations of racism and slander.

Members of the International Socialist Organization's Oakland branch have been passing out fliers in the Tri-City area that accuse anti-illegal-immigration activist Casey Fargo of posting a racist message on the Internet more than two years ago.

"We think it is really important to expose what these groups are really about," said Michael Smith, a member of the ISO. "And they are really about racism and xenophobia."

But Fargo, co-founder of the East Bay Coalition for Border Security, denies the charge and said he is considering taking legal action against the group.

The posting, dated Dec. 1, 2003, appears on the Web site of National Vanguard, a white supremacy group that claims to be "working for the long-term

interest of white people and...to build white community in towns and cities across the nation."

Attributed to Fargo on the site, the posting accuses the "Jewish-owned" media of being biased against whites and contains a headline that reads: "White Americans Regularly Suffer Extortion by Mexican Police."

Fargo said he did not author the piece and called the accusation a "slander campaign" against him because he co-founded the coalition, which opposes illegal immigration and granting amnesty to the nation's 12 million illegal immigrants.

"They're trying to defeat a messenger instead of the message," said Fargo, a co-organizer of several anti-illegal immigration rallies held in Fremont since May 1.

Meanwhile, Charles Dirkman, Fargo's friend and group co-founder, said that the anti-illegal-immigration organization has nothing in common with National Vanguard.

"National Vanguard is an evil, poisonous group based on nothing but destruction," said Dirkman, a 35-year-old Fremont resident. "That kind of stuff makes me want to puke."

Fargo said that the confusion about the posting stems from when he e-mailed a San Diego Union-Tribune column, which covered the robbery and rape of an American family by authorities in Mexico, to a wide-ranging list of media outlets. He e-mailed local TV stations, mainstream national newspapers, such as the New York Times, anti-immigration advocates such as Numbers USA, and civil rights groups, such as the Southern Law Poverty Center.

By including National Vanguard on the list, Fargo said that he was trying to share the story with as wide an audience as possible. He said the column must have been summarized and rewritten by someone at National Vanguard, who then attributed the published post to him.

"I didn't write what was posted, I just e-mailed the column to the Web site," said Fargo, a 25-year-old Livermore resident who works in Fremont.

Phone messages left this week at National Vanguard offices in California and Arizona were not returned.

Fargo said he will contact the National Vanguard to find out what happened.

He also said he plans to demand an apology from the International Socialist Organization, and that he may initiate legal proceedings against them "for slander and/or libel" for accusing him of authoring the Web message.

Fargo said that he has seen racist imagery that offended him on the white supremacist Web site. However, he added that he believes the term "racist" often is overused and that some are too quick to use it when they disagree with someone.

Smith didn't see it that way.

"I think you have to call a spade a spade and call people out," he said. "They're saying, 'Let's build a fence on the Mexican border — not the Canadian border — to keep out immigrants of a different skin color from Latin America who are coming here just so they can feed their families.' That is a racist thing to do."

Members of the International Socialist Organization, which favors giving amnesty to illegal immigrants, have been promoting their cause at Fremont and Union City BART stations in recent weeks.

"We've gotten a really good response," Smith said. "Fremont has a large immigrant population, and we want them to know that someone has their back. They should feel welcome here."

But Dirkman counters that his group merely opposes illegal immigration, and instead welcomes legal immigrants of all backgrounds.

The rising tension between the two groups, which have clashed — but avoided violence — at least twice at Fremont rallies in recent months, comes as they are expected to demonstrate again —tonight side by side at the intersection of Mowry Avenue and Fremont Boulevard.

More than two months after the May 1 pro-immigration protests were held nationwide, Congress still is trying to reconcile House and Senate immigration and border security bills.

The Senate bill provides a pathway for citizenship for illegal immigrants who have been here for five years or more. But the House bill, which the East Bay Coalition for Border Security supports, provides no such provisions and makes it a felony to be an illegal immigrant or to assist one.

Meanwhile, the coalition's leaders do not expect the controversy to hurt them.

"We have set up a structure where we can vote people in or out of office," Dirkman said. "And we have tons of good ideas that we're working on."

Staff writer Chris De Benedetti covers Fremont issues. He can be reached at (510) 353-7002 or cdebenedetti@angnewspapers.com.