BY JOHN HARWOOD
New York Times

The Obama White House’s decision to challenge Fox News appears driven equally by strategy and frustration. It is also a test case for politicians in both parties.

That is because partisan fragmentation throughout America’s news media and their audiences has grown significantly. Future Republican presidents will have to decide, as Team Obama has, how to buck or accommodate that trend.

Fox News has attracted the most attention because of its “fair and balanced” challenge to its competitors and its success. But the audiences of its competitors have tilted sharply in the other direction. (This reporter is chief Washington correspondent for CNBC and hosts “The New York Times Special Edition,” a program on MSNBC.)

Press critics worry that the rise of media polarization threatens the foundation of credible, common information that American politics needs to thrive. Will Feltus, a Republican specialist in voter targeting, does not.

If it complicates the choices facing leaders in Washington, Feltus argues, it also decentralizes political communication in a way that is both inevitable and healthy in the information age. “I feel no hand-wringing about it,” Feltus said. “People are smart enough to understand what color filter is over the lens.”

ROOTS OF A TREND

The evolution of political news on television, in print and on the Internet has a certain back-to-the-future feel. As the American Revolution approached in the 18th century, wrote William David Sloan and Julie Hedgepeth Williams in the book “The Early American Press, 1690-1783,” journalists “were expected to be partisan — intensely partisan.”

Feltus charted the rising partisanship of television news audiences using data from Scarborough Research, a partnership of the Nielsen Co. and Arbitron Inc.

In audience surveys from August 2000 to March 2001, Fox News viewers tilted Republican by 44.6 percent to 36.1 percent. More narrowly — 41.4 percent to 39.4 percent — so did the audience for MSNBC. The audiences of CNN, Headline News, CNBC and Comedy Central leaned Democratic.

Four years later, amid the Iraq war and President George W. Bush’s re-election campaign, the audience data had shifted. Fox News viewers had become 51 percent Republican and just 30.8 percent Democratic, while MSNBC viewers leaned Democratic by 41.7 percent to 40.4 percent. Viewers of CNN, Headline News, CNBC and Comedy Central grew slightly more Democratic.

By 2008-9, the network audiences tilted decisively, like Fox’s. CNN viewers were more Democratic by 50.4 percent to 28.7 percent;

MSNBC viewers were 53.6 percent to 27.3 percent Democratic;

Headline News’ 47.3 percent to 31.4 percent Democratic; CNBC’s 46.9 percent to 32.5 percent Democratic; and Comedy Central’s 47.1 to 28.8 percent Democratic.

BREEDING DIVISIVENESS

Those decade-long trends track deepening partisan passions and decisions by cable news programmers to amplify strong opinions. They help campaign strategists in both parties direct political ads.

“It makes it easier to find your voters,” said a Democratic pollster, Anna Greenberg. Mark Mellman, a strategist for the Democratic presidential nominee, John Kerry, in 2004, found that regular Fox News viewers supported Bush over Kerry by 88 percent to 7 percent — a more lopsided tilt than among gun owners, evangelical Christians or Iraq war supporters.

Mellman also said that the current media environment was a hothouse for political misinformation. The drift of public opinion during Obama’s presidency suggests that news coverage of the health care fight and other controversies has ratcheted up the intensity of sentiment among presidential allies and adversaries alike.

“It’s one more really powerful force that makes it difficult to get some sort of stable governing majority,” said a Republican pollster, Bill McInturff, who advised John McCain’s 2008 presidential campaign.

Obama’s aides signaled their unhappiness over that fact by criticizing Fox News as more an arm of the Republican Party than a practitioner of conventional journalism. They also sought to dissuade other news organizations from following Fox’s lead in trumpeting stories the White House views as a distraction from their governing priorities.

The success or failure of that effort may serve as a model for its White House successors. Though polarization among news audiences may be approaching its limit, given the partisan make-up of the electorate, there is no sign it is going away.

Feltus predicts the strategy will backfire by offending the subset of Fox viewers who Obama might otherwise be able to lure with his policies on issues such as health care. “If I were the Obama White House, I’d make my target uninsured people who watch Fox,” he said, because “I’ve got the answer to their problem.”

Besides, Feltus observed, winning over the other side starts with working to understand it. “As a Republican, I sometimes watch Keith Olbermann,” the MSNBC host, he said, though “I can usually only do it for 10 minutes.”