Throughout history, it’s been common for politicians to shade the truth when caught in a tight spot. But sometimes politicians push the limits, crossing the line into an Orwellian world where up is down, where bullies are victims, where people objecting to the lies are shouted down.

If that world seems familiar to Americans, it should. It is the world in which we’ve lived for the past seven or eight years under George W. Bush, as his clever operatives routinely turn truth inside out. Now, Hillary Clinton’s campaign is applying many of these same head-spinning tactics to win the Democratic presidential race.

I have spent my life studying the pictures and symbols of racism and slavery, and when I saw the Clinton ad’s central image — innocent sleeping children and a mother in the middle of the night at risk of mortal danger — it brought to my mind scenes from the past. I couldn’t help but think of D. W. Griffith’s “Birth of a Nation,” the racist movie epic that helped revive the Ku Klux Klan, with its portrayal of black men lurking in the bushes around white society. The danger implicit in the phone ad — as I see it — is that the person answering the phone might be a black man, someone who could not be trusted to protect us from this threat.

The ad could easily have removed its racist sub-message by including images of a black child, mother or father — or by stating that the danger was external terrorism. Instead, the child on whom the camera first focuses is blond. Two other sleeping children, presumably in another bed, are not blond, but they are dimly lighted, leaving them ambiguous. Still it is obvious that they are not black — both, in fact, seem vaguely Latino.

Finally, Hillary Clinton appears, wearing a business suit at 3 a.m., answering the phone. The message: our loved ones are in grave danger and only Mrs. Clinton can save them. An Obama presidency would be dangerous — and not just because of his lack of experience. In my reading, the ad, in the insidious language of symbolism, says that Mr. Obama is himself the danger, the outsider within.