Raw racism may never be vanquished, but nowadays it generally travels in private paths or public codas. But not always. Consider the sign boldly printed in white paint on the back of a camper top on a pickup truck seen Monday morning on Highway 127 by Signal Mountain's shopping plaza. It read: "Name one government successfully run by a Negro in the history of the world."

The bottom line's bookends were an NRA logo and a bumper sticker that read, "Fear the government that fears your gun." The truck had a Tennessee tag.

The driver's sign, odious as it is, is protected by our free-speech rights. Still, it's a useful object lesson: it confirms, as if more proof were needed, that the blatant racism long directed at President Obama's administration remains fiercely deep-seated.

Newt Gingrich's racist taunts provide another example. He has accused Obama of "Kenyan, anti-colonial behavior," mixing the African heritage of Obama's father with that of an insurrectionist in what can only be construed as a concocted racial smear.

He also has repeatedly referred to President Obama as "the greatest food-stamp president in history." That's both an errant and irrelevant claim. The number of food-stamp recipients rose more under George W. Bush, and food-stamp eligibility is based on income, not presidential whim. But never mind. Gingrich's point is to evoke racial stereotypes.

His reckless rhetoric hardly stands alone among the GOP's right wing. Tea party leaders have consistently railed about their wish to "take their country back," as if it's been abducted and sabotaged by unworthy leaders. They've also chanted about the "tree of liberty" being replenished by blood.

Such inflammatory rhetoric dangerously evokes an American history of racial and political violence. That was made plain when rancorous GOP objections to health care reform, of all things, became so virulent that gun rights advocates took to openly brandishing rifles at political town hall meetings over the issue in 2009.

More recently, Rick Santorum has raised the conspiracy temperature by suggesting that the medieval Crusades could be analogous to a defense against "the American left who hates Christendom." Among others, he's also suggested that global warming is merely a pretext for "a beautifully concocted scheme" by Democratic leftists to create "an excuse for more government control of your life."

Ron Paul claimed in his early newsletters that both the Civil War and the Civil Rights Act were blunders. Virtually all of the Republican presidential aspirants, among other GOP leaders, have harped on Obama for "apologizing" for American actions abroad, a gross distortion of his actual remarks.

The drumbeat against Obama ignores hard-earned, humane achievements -- in economic recovery, health care reform, exiting Iraq, helping Libya's rebellion, healing foreign relations. Racism and demonizing rhetoric are blind to facts, but they are too dangerous to ignore.