An anti-Prop 8 group on Wednesday announced it has targeted the Salt Lake City-based Ken Garff automotive dealerships in retaliation for $100,000 donated by the CEO's wife to supporters of a California ballot proposition eliminating same-sex couples' right to marry.

Fred Karger, founder of Californians Against Hate, said the boycott will use an Internet campaign to ask people to boycott the automotive's 40 dealerships in Utah, California, Texas and Iowa.

Karger accused CEO Bob Garff of "hiding behind his wife's skirts" by claiming the $100,000 donation was a personal gesture. At a news conference in Salt Lake City, Karger also said the cash was "a family contribution" that was derived from dealership revenues.

Garff's wife, Katharine, gave to ProtectMarriage.com a week before the Nov. 4 election that overturned a state Supreme Court decision legalizing same-sex marriage, according to filings with the California Secretary of State's Office.

Katharine Gaff was out of town but her son, John Garff, who is company president, said the donation was "a personal decision based on my mother's personal conviction of marriage. It had nothing to do with my father, who supported her decision, with me or with the company."

"Our company has been politically neutral for decades," said John Garff. "We literally spend zero to a few hundred dollars annually on political or lobbying campaigns of any kind."

Garff also pointed to the company policy against harassment or discrimination of any kind in the workplace, and benefit packages that are favorable for gay and lesbian employees.

But Karger brushed aside those efforts, saying gay marriage is a matter of "civil rights and equal rights."

Karger said he welcomed the possibility of meeting with Garff company officials. And shortly after the news conference, John Garff invited him to company headquarters on Main Street.

Californians Against Hate has launched three previous boycott campaigns, two before the November election and one since Proposition 8 passed. This is the first outside California.

Karger said a boycott of organic foods producer Bolthouse Farms in Bakersfield, Calif., eventually won significant concessions from the company, including a sizeable donation to gay and lesbian causes in California and recognition of civil unions for its employees.

Bolthouse spokesman Bryan Reese did not discuss the boycott Wednesday but said in a statement: "Our philosophical heritage manifests itself in business through the mutual respect, personal dignity and equitable treatment of all of our customers, employees, vendors and associates. This philosophy includes the LGBT (lesbian, gay, bisexual and transgender) community in every aspect of our operation and philanthropy."