It was cool and rainy Sunday morning when the bomb ripped through the building. At 10:22, a group of children was just heading into the basement to hear a sermon at the 16th Street Baptist Church in Birmingham, Ala. According to a Washington Post account at the time: Dozens of survivors, their faces dripping blood from the glass that flew out of the church's stained glass windows, staggered around the building in a cloud of white dust raised by the explosion.

Four girls were killed. The head of one little girl was found far from her body. Twenty-two others were injured. Wandering through his devastated church, the Rev. John H. Cross found a megaphone and asked the enraged and stunned crowd to disperse. "The Lord is our shepherd," he sobbed, "we shall not want."

This week, Congress marked the 50th anniversary of that terror attack by posthumously awarding the Congressional Gold Medal to Denise McNair, Carole Robertson, Addie Mae Collins and Cynthia Wesley.

We Americans are not confused about the morality of what happened in Birmingham that September morning in 1963, nor during the Jim Crow era in America generally. We do not hesitate to condemn utterly the behavior and the beliefs of the Ku Klux Klan (the perpetrators of this bombing and others) and their white supremacist fellow travelers. We do not worry that reviling white supremacists and their grotesque deeds will somehow taint all white people.

But when it comes to other groups and other motives for the same kind of terrorism — we lose our moral focus. Bill Ayers, Bernadine Dohrn and Kathy Boudin have become honored members of the faculties at leading universities. Ayers is even the friend of the president of the United States. Regarding his own record of setting bombs that kill and dismember innocent people, Ayers told The New York Times on the ironic date of Sept. 11, 2001 that "I feel we didn't do enough ... (there's) a certain eloquence to bombs, a poetry and a pattern from a safe distance." So says a retired "distinguished professor" at the University of Illinois at Chicago.

Today, American liberals are obsessed not with terrorism but with the color and ethnicity of terrorists. They can readily enough attribute violent tendencies to groups they dislike — the tea party, for example, which hasn't committed so much as a littering offense. But when it comes to Islamic terrorism, their voices falter.

Attorney General Eric Holder, asked whether three attacks on the United States (the underwear bomber, the Times Square bomber and Maj. Nidal Hassan) could be attributed to "Islamic" radicalism, refused to say so. Asked repeatedly whether religious motives played a role, Holder would say only, "there are a variety of reasons why people have taken these actions." Janet Napolitano has been quick to dismiss terror attempts as "one offs." Would Holder and Napolitano say the same about white supremacists? Each one had his own motivations and we can't surmise what those factors were?

There is a tendency among many on the left to temper their disgust and indignation at political violence (i.e. terror) if the terrorist is from the "correct" group. "Muslim ... means not being white" Peter Beinert writes in the Daily Beast.

Beinert and other liberals imagine that the U.S. is a cauldron of teeming racism with the lid barely kept down. At the first acknowledgment that Islamists (some, but by no means, all of whom are dark skinned) present a continuing threat, the lid will fly off and white American vigilantes, given permission, will start shooting black and brown people on the streets, burning their shops, and bombing mosques.

The hatred that Islamism preaches, lauds and inspires is a nuisance, liberals may concede. But the hatred in the heart of "white America" is the greater danger.

Mona Charen's column is released once a week.
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