A block thrown through a home window. Cars vandalized. Hate-filled anonymous phone calls at home and work. Swastikas scrawled on houses of worship. Physical assaults. Dismissal from employment because of political views.

Are these examples of retaliation against civil-rights activists in the South in 1954? Attempts by an authoritarian government to quash dissent?

No, this is the sort of intimidation that Americans who support marriage as the union of a man and woman can face today. Persecution of opponents is becoming a tool of the trade for some gay-marriage activists, who -- ironically -- seem to view themselves as beacons of tolerance.

Now, the groundwork for such intimidation is being laid in Minnesota.

In an early skirmish in the battle over the marriage amendment, which will be on the ballot in 2012, the state Campaign Finance Board has issued a ruling that could require a nonprofit organization to disclose the identity of supporters if that organization contributes to the marriage-amendment campaign.

The board's ruling breaks with the interpretation of the law in other recent amendment campaigns, and is an attempt to change the rules in midstream.

As a result, Minnesotans who believe that gay people have a right to live as they wish, but who oppose redefining marriage, may find their civil rights, livelihoods or safety threatened if they dare to oppose what's becoming politically correct orthodoxy.

The people of California can tell you where disclosure rules can lead. Each of the incidents I opened this column with occurred there during the 2008 debate over Proposition 8, the state's marriage amendment.

Ask the restaurant manager who was forced to resign after her $100 donation triggered a street protest and a boycott of her establishment.

Ask the dentist who lost patients, the family-owned creamery that endured protests and retaliation, or the lawn sign distributor and the elderly lady who were assaulted as they peacefully expressed their views.

These days, however, harassment and reprisals aren't confined to election season.

In North Carolina in June 2011, for example, corporate leadership consultant and motivational speaker Frank Turek was fired by Bank of America after someone there learned he had written a book opposing same-sex marriage.

In Turek's words, "I was Googled, I was outed, I was fired for being somebody who has a traditional marriage viewpoint."

North Carolina defines marriage as the union of one man and one woman, as do 43 other states. Citizens there support one man/one woman marriage by 61 percent to 34 percent. Yet you can still lose your job in North Carolina for publicly daring to cross the new Diversity Ayatollahs.

Given this reality, we need an organization to defend Americans who face reprisals merely because they exercise their fundamental civil rights.

Now we have it: the Marriage Anti-Defamation Alliance (MarriageADA), whose spokesperson, Maggie Gallagher, is a cofounder of the National Organization for Marriage. MarriageADA exists to protect and defend people like Turek.

These people could include the school guidance counselor whose counseling license activists sought to revoke after he appeared in a television ad for one man/one woman marriage during a ballot referendum in Maine.

Or the wedding photographer who was sued and ordered to pay a nearly $7,000 fine for declining to photograph a same-sex commitment ceremony in New Mexico.

Or the couple in Vermont who declined to host a same-sex wedding reception at their inn because of their Christian faith.

MarriageADA's larger mission is to fight back against the attempt of media, entertainment and political elites to convince the rest of society that belief in marriage as a male/female institution -- the form it has taken across the world and throughout history -- is equivalent to racial bigotry.

This out-and-out falsehood is having a chilling effect in workplaces across the country.

For example, if you work for a large corporation -- even in a "one man/one woman" marriage state like Minnesota -- you may face uncomfortable pushback at your job if you voice your support for traditional marriage, or donate to a protraditional marriage group.

If you donate to a group supporting gay marriage, of course, you face no such penalty.

America's need for MarriageADA should open our eyes to the increasingly Orwellian situation we face. It's becoming an act of civic courage -- as speaking out against Jim Crow in the South once was -- to support marriage as a bedrock male/female social institution, and to state your belief that children need a mother and a father.

This raises a troubling question: If gay marriage supporters can intimidate and silence their opponents while one man/one woman marriage remains the norm, to what authoritarian extremes will they go if same-sex marriage becomes the law of the land?

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Katherine Kersten is a senior fellow at the Center of the American Experiment. The views expressed here are her own. She is at kakersten@gmail.com.