Recent questions about the credibility of NBC News Anchor Brian Williams – following revelations of apparent war-story fabrications – haven’t done much to hurt the public’s perception of NBC News.

That’s according to this year’s annual Public Policy Polling survey on TV news, which is evenly divided when it comes to NBC News. Forty percent of respondents say they trust the network’s coverage, while 40 percent say they don’t.

Last year, the responses ran about the same: 39-39.

“Just like everything these days, voters are polarizing about it, across party lines,” said PPP Director Tom Jensen. “Overall, voters are pretty evenly divided. Thirty-nine percent say William should be able to keep his job. Thirty-six percent say he should be let go.

“But when you break that down by party, Democrats are pretty sympathetic toward Williams, by a pretty strong margin. And then you look at Republicans – Republicans say he should be fired.”

It’s not just issues such as abortion and gay marriage that polarize voters these days, according to Jensen. Now we can add our TV news choices to that list.

This year, as in past years, Fox News is both the most trusted and the least trusted source of news in the nation.

“Republicans said that they trusted Fox News,” said Jensen,” and they said that they didn’t trust a single other thing that we polled on. Every single one of the major networks – NBC, CBS, ABC – fewer than 25 percent of Republicans trust them.

“And then when you look at Democrats, they trust everything except Fox News.”

The most trusted news network among Democrats, by a narrow margin, is CNN, at 21 percent. PBS comes in second, at 18 percent.

Overall, the only news outlet that a majority of Americans say they trust is PBS, by 52 percent.