Tara Servatius, a blogger for the John Locke Foundation, a "free-market think tank" in Raleigh, N.C., resigned on Thursday after posting an offensive cartoon of President Obama on the foundation's blog earlier in the week.

According to the Charlotte Observer, the cartoon showed a chained Obama wearing high heels and standing over a bucket from Kentucky Fried Chicken, combining a series of sexually and racially charged images into one drawing. It accompanied a blog post from Monday in which Servatius argued that Obama's opposition to a ban on gay marriage in North Carolina was a calculated move to increase the vote among young Obama-supporting professionals in the state.

Servatius issued a statement saying she was "genuinely sorry my inclusion of the photo along with my blog post has caused controversy."

But the conservative blogger also defended her inclusion of the photo as an attempt to articulate her position "At the time, I was searching for a picture of the president in drag to illustrate his Southern political strategy of courting young voters, a majority of whom support gay marriage," Servatius wrote. "It was one of the first photos to come up on Google Images. Regrettably, I didn't think about the racial implications of the picture when I posted it. I simply don't think in those terms. Unfortunately some people do. To me, fried chicken is simply a Southern cuisine. So the picture seemed perfect to illustrate Obama's Southern strategy."

For its part, the John Locke Foundation seemed to disavow Servatius in its statements. Its president, John Hood, described her on his Facebook page as a "freelancer," calling the image "offensive and utterly inappropriate." Hood lamented the incident as evidence of the negative tone of politics in the country. "This is the kind of episode that can only make the situation worse. We should be able to disagree about controversial issues without it coming to this," he wrote.

Rick Henderson, the managing editor of the foundation's journal, told the Charlotte Observer that "no one at the John Locke Foundation saw, read, or reviewed the posting or the image before the item was posted on the blog. We typically do not review blog items prior to publication."

Also on HuffPost: