There’s been a lot of suggestions that President Obama’s approval rating is in steep decline. There is some evidence for the view that this is a statistical artifact — the product of an outlier CNN poll that inflated his approval numbers. But there’s also evidence for the opposite view: that it reflects a genuine shift in Obama’s standing.

Key to Obama’s overall standing is the public’s trust in government. As Harry Enten notes, a president does best when Americans are willing to believe the best about the government and its actions. But revelations over surveillance by the National Security Agency — as well as the assorted scandals of last month — has harmed general trust in government.

Remember, only a plurality of Americans believe that the NSA should have the power to collect huge amounts of information on the online lives of citizens. A poll released last week by the Washington Post and the Pew Research Center, for instance, found 45 percent support for the NSA program (look for the final question in the survey). And in a survey released today by CNN, 47 percent of respondents say the White House was involved in IRS targeting of conservative groups, a perception that’s far from the facts, but easy to explain given media attention and Republican rhetoric.

The combination of all of this has led to declining trust in government. According to a recent NBC/WSJ poll, 55 percent of Americans said the IRS scandal made them doubt the “overall honesty and integrity” of the White House. Likewise, in a Fox News poll released after the NSA revelations, only 48 percent said that the president was “honest and trustworthy.” And at the same time as all of this, Obama’s approval has taken a slow dip in the Gallup tracking poll — it’s at 47 percent, the lowest since he was reelected.

The CNN survey of Obama’s approval might be off, but there’s plenty of evidence in favor of the view that the president has lost real support as a result of revelations and controversies over the last month. Indeed, you can read Obama’s widely publicized interview with Charlie Rose on the NSA program as an attempt to reassure Americans and regain lost trust. The question, then, is whether this is too little, too late.

Jamelle Bouie is a staff writer at The American Prospect, where he writes a blog.