African-Americans targeted for harassment. Swastikas scrawled on churches and religious books burned. Homes defaced and people hounded from their jobs because of their political beliefs.

Has the Ku Klux Klan returned? Are neo-Nazis or fundamentalist right-wing hate groups on the rise?

Guess again. This is the work of a sizable number of activists who have decided that any bullying, brown-shirt tactic is fair game in their battle to impose gay marriage on America.

One skirmish in that battle played out last week. In Perry vs. Schwarzenegger, four gay plaintiffs have sued to overturn Proposition 8 -- the 2008 amendment that California voters added to their state's constitution to ensure that marriage remains the union of one man and one woman. Plaintiffs claim the amendment violates the U.S. Constitution and seek judicially imposed same-sex marriage in all 50 states.

On Wednesday, the U.S. Supreme Court rejected federal District Judge Vaughn Walker's decision to broadcast proceedings on YouTube. Defendants argued that such a broadcast would increase witnesses' vulnerability to intimidation and harassment.

What do they fear?

Take, for instance, the bullying tactics on display during the campaign for Proposition 8. Supporters who put signs in their yards risked a brick through their living-room windows, spray paint on their garages and vandalized cars. One woman reported finding her staircase covered in urine. In another case, two women parked an SUV in front of a Prop 8 supporter's home, with an arrow and the words "Bigots live here" scrawled on the window.

Blacks were singled out for persecution, since they favored Prop 8 in large numbers. Time magazine cited eyewitness reports that racial epithets were used at anti-Prop 8 protests.

Activists also targeted religious institutions, reserving special venom for Mormons. After Prop 8's passage, at least 17 Mormon houses of worship were defaced, and a suspicious white powder was mailed to two others. At one temple, the Book of Mormon was torched on the doorstep.

Gay-marriage activists made skillful use of public data to harass citizens who donated to the "Yes on 8" campaign. One website, "eightmaps.com," displayed a map that enabled activists to pinpoint the identity, employer, donation size and location of certain Prop 8 supporters. Another site, sponsored by a group called Californians Against Hate, revealed some Prop 8 donors' addresses and telephone numbers. The San Francisco Chronicle and Los Angeles Times also posted search engines that facilitated targeting of this kind.

Not surprisingly, many Prop 8 supporters were bombarded with harassing calls and e-mails. Some lost their jobs, including Scott Eckern, artistic director of the California Musical Theatre in Sacramento, and Richard Raddon, president of the Los Angeles Film Festival. Both resigned after their private donations were publicized and activists threatened to boycott their organizations. Dozens of businesses -- including hotels, insurance agencies, accounting firms and dentist offices -- were similarly targeted because of their owners' or employees' private donations.

Even ordinary folks had reason to fear. After Prop 8 passed, gay activists mobbed El Coyote, a restaurant in Los Angeles, calling for a boycott because the owner's daughter, Margorie Christoffersen, had donated $100 in support of the measure. Shouting "shame on you," they hurled vulgarities at diners. Though Christofferson apologized, "boisterous street protests erupted" after she refused to renounce her stance, according to the Wall Street Journal. Christoffersen took a leave of absence.

Maggie Gallagher, president of the National Organization for Marriage, summed up the situation this way. "The same-sex marriage movement," she wrote, has revealed itself as "a political tsunami which will brook no dissent and openly seeks to punish Americans who disagree with its new dogmas."

Events in California reveal a troubling double standard on the part of gay activists. While they demand tolerance from others, many appear to view tolerance as a one-way street.

The mainstream media have also betrayed a double standard. If gay-marriage supporters were being harassed and hounded from their jobs, the press would rightly raise an outcry. Instead, the Los Angeles Times applauded a virulent anti-Mormon TV ad and editorialized that "equal rights" campaigns often require years of "in-your-face radicalism."

In California, we have a wake-up call about the high stakes in the same-sex-marriage debate. Activists' bullying tactics signal an authoritarian mindset -- the ends justify the means -- that threaten to shape events in our schools, our workplaces and our houses of worship if same-sex marriage is imposed.

Katherine Kersten is a Twin Cities writer and speaker. Reach her at kakersten@gmail.com.