The smearing of Shirley Sherrod ought to be a turning point in American politics. This is not, as the now-trivialized phrase has it, a "teachable moment." It is a time for action.

The mainstream media and the Obama administration must stop cowering before a right wing that has persistently forced its propaganda to be accepted as news by convincing traditional journalists that "fairness" requires treating extremist rants as "one side of the story." And there can be no more shilly-shallying about the fact that racial backlash politics is becoming an important component of the campaign against President Obama and against progressives in this year's election.

The administration's response to the doctored video pushed by right-wing hit man Andrew Breitbart was shameful. The obsession with "protecting" the president turned out to be the least protective approach of all.

The Obama team did not question, let alone challenge, the video. Instead, it assumed that whatever narrative Fox News might create mattered more than anything else, including the possible innocence of a human being outside the president's inner circle.

Obama complained on ABC's "Good Morning America" that Agriculture Secretary Tom Vilsack "jumped the gun, partly because we now live in this media culture where something goes up on YouTube or a blog and everybody scrambles." But it's his own apparatus that turned "this media culture" into a false god.

Yet the Obama team was reacting to a reality: the bludgeoning of mainstream journalism into looking timorously over its right shoulder and believing that "balance" demands taking seriously whatever sludge the far right is pumping into the political waters.

This goes way back. Al Gore never actually said he "invented the Internet," but you could be forgiven for not knowing this because the mainstream media kept reporting he had.

There were no "death panels" in the Democratic health-care bills. But this false charge got so much coverage that an NBC News-Wall Street Journal poll last August found that 45 percent of Americans thought the reform proposals would likely allow "the government to make decisions about when to stop providing medical care to the elderly." That was the summer when support for reform was dropping precipitously. A straight-out lie influenced the course of one of our most important debates.

The traditional media are so petrified of being called "liberal" that they are prepared to allow the Breitbarts of the world to become their assignment editors. Mainstream journalists regularly criticize themselves for not jumping fast enough or high enough when the Fox crowd demands coverage of one of their attack lines.

Thus did Post ombudsman Andrew Alexander ask this month why the paper had been slow to report on "the Justice Department's decision to scale down a voter-intimidation case against members of the New Black Panther Party." Never mind that this is a story about a tiny group of crackpots who stopped no one from voting. It was aimed at doing what the doctored video Breitbart posted set out to do: convince Americans that the Obama administration favors blacks over whites.

And never mind that, to her great credit, Abigail Thernstrom, a conservative George W. Bush appointee to the U.S. Commission on Civil Rights, dismissed the case and those pushing it. "This doesn't have to do with the Black Panthers," she told Politico's Ben Smith. "This has to do with their fantasies about how they could use this issue to topple the [Obama] administration." Instead, the media are supposed to take seriously the charges of J. Christian Adams, who served in the Bush Justice Department. He's a Republican activist going back to the Bill Clinton era. His party services included time as a Bush poll watcher in Florida in 2004, when on one occasion he was involved in a controversy over whether a black couple could cast a regular ballot.

Now, Adams is accusing the Obama Justice Department of being "motivated by a lawless hostility toward equal enforcement of the law." This is racially inflammatory, politically motivated nonsense -- and it's nonsense even if Sean Hannity and Rush Limbaugh talk about it a thousand times a day. When an outlandish charge for which there is no evidence is treated as an on-the-one-hand-and-on-the-other-hand issue, the liars win.