During CNN's August 28 coverage of the Democratic National Convention, CNN contributor Alex Castellanos falsely claimed that Sen. Barack Obama has never held a job for four years. Castellanos said of Obama: "[T]he next thing you know, he's running for the president of the United -- presidency of the United States, when -- you know, a four-year job, when he's never held a job that long in his life." In fact, Obama taught at the University of Chicago Law School from 1992-2004, served in the Illinois senate from 1997-2004, and held positions as associate and of counsel at the law firm of Miner, Barnhill & Galland (known as Davis, Miner, Barnhill & Galland when Obama joined) from 1993-2002.

As Media Matters for America has noted, some of Castellanos' CNN remarks since May include his saying of a characterization of Sen. Hillary Clinton as a “white bitch,” "[S]ome women, by the way, are named that and it's accurate" (for which he apologized); suggesting that Clinton would poison Obama; and falsely suggesting a link between 9-11 and Iraq. The New York Times reported on August 10 that Castellanos is a “member of [Sen. John] McCain's panel of outside advertising consultants.”

From the 9 p.m. ET hour of CNN's August 28 coverage of the Democratic National Convention:

BLITZER: Let me ask Alex Castellanos, our Republican strategist. Talk about the -- this is a symbolically important step that these Democrats are doing to try to show that the military is behind Barack Obama and that when it comes to national security, he won't take anyone's back seat.

CASTELLANOS: You know, this is the brand-new product on the shelf that you've never tried and you're wondering whether to buy it or not, and so what do you want? You want endorsements, you want other people who've seen the show, to tell you how good it was. And so he's surrounding himself as much as possible with credibility. You know, the danger, I think, tonight for the Democrats -- I think what Republicans are looking for is, are the Democrats gift-wrapping air, here? Is this a great sight, great spectacle, great colors, but is there enough substance to it?

You know, Barack Obama still has the challenge of -- just a few years ago, he was a state legislator, he was a community activist, he was voting present a few hundred days in the Senate. And the next thing you know, he's running for the president of the United -- presidency of the United States, when -- you know, a four-year job, when he's never held a job that long in his life. So he's trying to surround himself with as much credibility and with as much popularity as he can.

ANDERSON COOPER (co-host): Certainly the same kind of arguments that were made against John F. Kennedy, who is the other Democratic presidential candidate who decided to take his acceptance speech outside the convention hall in Los Angeles to the Coliseum.