Nearly 40 years ago, then-Vice President Spiro Agnew awakened Republican politicians to a surefire crowd pleaser by ripping into one of their favorite bogeyman, "the liberal media," which he did with a withering critique of network television news.

Carrying out the wishes of his press-hating boss, Richard M. Nixon, Agnew said in a speech in Des Moines, Iowa, that TV anchors "not only enjoy a right of instant rebuttal to every presidential address, but, more importantly, wield a free hand in selecting and presenting and interpreting the great issues in our nation."

He was a lover of alliteration, so it was pretty clear who he was including when he later referred to "nattering nabobs of negativism."

You surely remember Agnew. He resigned the vice presidency in disgrace in 1973 after being charged with tax evasion and money laundering while governor of Maryland.

But ever since his broadsides at the mainstream media, GOP candidates have found press-bashing irresistible, knowing there is no quicker way to get conservatives riled up than to tell them what they love to hear.

"Running against the elite media … certainly has resonance among Republican base voters," Mark Jurkowitz of the Pew Center for Excellence in Journalism recently told the Associated Press. "In conservative circles, there's been the perception that the media are tilted against them."

Newt Gingrich brought the audience to its feet at one of the recent Republican debates by challenging the questioner, CNN's John King, who merely offered Gingrich a chance to respond to a charge by one of his former wives that he wanted an open marriage.

"I think the destructive, vicious, negative nature of much of the news media makes it harder to govern this country, harder to attract decent people to run for public office," said a self-righteous Gingrich. "And I am appalled that you would begin a presidential debate on a topic like that. I am tired of the elite media protecting Barack Obama by attacking Republicans."

The crowd roared its approval, evidently believing it is OK to commit adultery as long as nobody asks you about it. So much for family values. Also overlooked was the fact that some of the harshest criticism of fellow Republican candidate Mitt Romney has come from Gingrich himself, not the media.

Such visceral reaction can bear little or no resemblance to what actually appears in the newspapers, online or on television day in and day out, but "the liberal media" image is fueled, interestingly enough, by "the conservative media," as represented especially by Fox News and the crown prince of talk radio, Rush Limbaugh.

It would be foolish to suggest that bias from either the left or the right never seeps into news coverage. But readers and/or viewers often can't or won't make the distinction between straight news stories, editorials, commentaries and opinion columns. And they increasingly reject any information or opinion that does not validate their own biases and prejudices.

Strangely enough, you rarely hear Democratic candidates and/or their allies bashing "the conservative media," even though, for instance, they have ample reason to question Fox's "fair and balanced" slogan. Either they have a more even temperament, or the right just enjoys a more receptive, quick-to-anger audience.

There are always studies being done to determine media bias, but the ones that usually come down the hardest on the idea of a "liberal media" usually come from conservative-leaning think tanks and academicians.

One such study at UCLA a few years ago determined there was a "strong liberal bias," and it got widespread attention. But it failed to point out that the study was done by former fellows of a conservative think tank and writers for a right-wing magazine, the American Spectator.

The findings were subsequently labeled by other analysts as "next to useless."

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William Endicott is a former deputy managing editor of The Bee.

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