For anyone who thinks Fox News Channel's “fair and balanced” claim is malarkey, you’re not alone.

On Wednesday, Public Policy Polling, or PPP, released its annual survey on the trustworthiness of TV news, and the results have the media world abuzz over what is being seen as a decline in credibility for the Fox News Channel. News Corp.’s (Nasdaq:NWSA) ratings powerhouse hit a record low in trustworthiness this year, with 46 percent of registered voters saying they do not trust the network. That’s up from 37 percent four years ago when PPP first began taking the poll.

Those percentages may not seem very staggering at first, but they get more pronounced among viewers who should be Fox’s biggest cheerleaders: self-identifying conservatives.

This is where things get disconcerting for Fox. Last year, 65 percent of respondents who identified as “somewhat conservative” said they trust Fox as a news source. This year, that number is down to 52 percent. That’s a decline of 13 percentage points and among the steepest shifts in the entire survey.

Among moderate conservatives who said they do not trust Fox News, a similarly sizable shift is seen: Last year, 18 percent said they did not trust the network, while this year that number jumped to 32 percent.

Indeed, even respondents who identified themselves as “very conservative” appear to have less of a stomach for Fox News, with 13 percent this year saying they don’t trust the network, compared to just 6 percent last year. While many conservatives say PPP is a left-leaning organization whose statistics should be taken with a grain of salt, even some prominent right-leaning media critics say Fox executives should be paying attention to these latest figures.        

“There is plenty of data in the PPP survey, and I agree that some of it could be troubling for Fox News,” Mark Finkelstein, a senior contributor for the conservative website NewsBusters, said in an email. “The fact that they let Dick Morris go is surely a reflection of their recognition that there’s some housekeeping to do. I would ascribe much of the decline in conservatives’ trust in Fox with their generally foul post-election mood.”

Interestingly, Fox’s credibility has remained virtually unscathed among those whose post-election mood should be the foulest: members of the Republican Party. Some 70 percent of respondents who identified as "Republican" still say they trust Fox News, a decline of only 3 percentage points from the year before. The numbers show what may be a growing disconnect among conservative voters who believe the Republican Party -- and Fox News along with it -- has swayed too far from their core values.   

“It’s not a partisan thing but an ideological thing,” Tom Jensen, PPP’s director, said. “I think a lot of people watching Fox News this year thought they became a Republican channel as opposed to a conservative channel.”

Jensen cited the final laps of the presidential election -- when many Fox personalities spent the better part of three months displaying an unshakable faith in Mitt Romney -- as the likely catalyst for conservatives’ disillusionment. He added that those looking for some semblance of objectivity may have been left feeling duped, whether it was by Sean Hannity’s far-off predictions of a Romney win or Karl Rove’s demonstrative election-night meltdown.

“A lot of that stuff had to do with winning the election,” Jensen added. “I think people felt like Fox was just pumping the Republican candidate, when a lot of conservatives didn’t even like Mitt Romney.”

Jensen added that a rift between viewers’ party and their ideology could potentially hurt Fox News more than a similar divide would damage its left-leaning rivals. “We see much more party diversity among conservatives than we do liberals,” he said. “A lot of conservatives identify as ‘independent’ or ‘other,’ whereas almost all liberals vote Democrat.”

Whatever the reason, Fox’s credibility decline is reflected in its ratings. It is still the most-watched cable news network, but, compared with CNN and MSNBC, it has also had the most difficult time bouncing back from the post-election ratings slump. Even worse, this January, Fox’s prime time ratings for the key demographic of 25 to 54 fell to their lowest levels in almost 12 years.

Falling ratings and diminished credibility aside, it’s important to note that Fox is still identified as the most-trusted news source by more Americans than any other outlet -- and by a pretty wide margin. Of the 800 registered voters polled by PPP, 34 percent say they trust Fox over any other network. Trailing in a distant second place is PBS, with 13 percent. MSNBC, Fox’s liberal counterpart, was called most-trusted by only 8 percent of respondents.

That number may not be surprising seeing how left-wing punditry has always been a tougher sell. (Remember Air America radio?) But before MSNBC or any news outlet gloats too much over Fox’s credibility decline, Jensen offered a sobering bulletin: You’re all in the same boat.          

“Fox has gotten a lot of attention with this poll, but, aside from PBS, almost everybody was down this year,” he said. “People are less and less trusting of TV news.”

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