(Pablo Martinez Monsivais/AP Photo)

An email from the Obama campaign encapsulates the problem when political campaigns seize the language of fact checkers, muddying the waters.

In the note, sent later in the day today, Obama campaign deputy campaign manager Stephanie Cutter invites supporters to "report an attack" at the Truth Team report page.

"Received a robo-call or an email forward full of falsehoods?" the page asks. "Found a misleading leaflet in your mail? Tell us about it, and help fight back against the attacks on President Obama and his record."

Cutter in her email hammers Mitt Romney for saying "Since President Obama assumed office three years ago, federal spending has accelerated at a pace without precedent in recent history," which she refutes with a Market Watch blog saying that federal spending is rising at the slowest pace since President Eisenhower.

Here's the problem: the Market Watch item has been refuted by several fact checkers as severely flawed, notwithstanding its citation by White House press secretary Jay Carney along with the assertion that reporters should "not buy into the BS that you hear about spending and fiscal constraint with regard to this administration. I think doing so is a sign of sloth and laziness."

The Washington Post's Fact Checker gave Carney three Pinocchios, writing that the "data in the article are flawed, and the analysis lacks context - context that could easily could be found in the budget documents released by the White House."

The Associated Press came to a similar conclusion, saying that "the problem with that rosy claim is that the Wall Street bailout is part of the calculation. The bailout ballooned the 2009 budget just before Obama took office, making Obama's 2010 results look smaller in comparison. And as almost $150 billion of the bailout was paid back during Obama's watch, the analysis counted them as government spending cuts. It also assumes Obama had less of a role setting the budget for 2009 than he really did. … The analysis simply looks at the year-to-year topline spending number for the government but doesn't account for distortions baked into the figures by the Wall Street bailout and government takeover of the mortgage lending giants Fannie Mae and Freddie Mac."

Cutter also hammers Romney on classroom size, saying, "Mitt Romney made some more ridiculous claims and assertions this week, this time on education policy. He even had the nerve to tell a group of educators that: 'It's not the classroom size that's driving the success of those school systems.'"

The problem is that Obama's education secretary, Arne Duncan, has also suggested classroom size isn't as important as some necessarily think.

"We spent billions of dollars to reduce class size. As a parent, we all love small class size," Duncan told MSNBC's Andrea Mitchell. "But the best thing you can do is get children in front of an extraordinary teacher. So other countries have higher class sizes but extraordinary talent in those rooms."

Leonie Haimson, the executive director of Class Size Matters, recently wrote an open letter to President Obama that appeared in the Washington Post, saying, "If you disagree with what Romney said, you should rein in your own education secretary and ask him to take back his erroneous statements on the subject."

Cutter wrote: "Mitt Romney's general disregard for the truth is why you all are so important to this campaign. So many Truth Team members have told me: You give us the facts to get the President's back, and we'll get it done."

But voters should generally beware of campaigns claiming that they are fact checking. They have an interest in conflating nonsense - like the bizarre assertion that President Obama was born in Kenya - with legitimate criticisms. They want all attacks to be dismissed as falsehoods - and that is simply not the case.

- Jake Tapper