New York Times columnist Paul Krugman has been battling with the campaign of Sen. Barack Obama for a little while now. In his column Monday, Krugman examined the differences between the healthcare plans offered by Obama and Sen. Hillary Clinton. But it was a blog post he wrote Tuesday that has really gotten the attention of the Clinton campaign.

In the post, "More Obama ugliness on health care," Krugman looks at comments Obama made on CNN Tuesday, which Time's Mark Halperin had paraphrased as, "Obama likened Clinton's health care mandate proposal to eliminating homelessness by requiring everyone buy a house." That prompted Krugman to say, "The Clinton plan does every bit as much to ensure affordability as the Obama plan. This is just grotesque. ... There are no excuses this time. You can't say that it's the work of some staffer. This is unscrupulous demagoguery from the candidate himself."

The Clinton campaign has been doing its best to ensure that reporters are aware of Krugman's comments; in the conference call we covered earlier, staffers brought it up, and included it in a later e-mail as well.

For what it's worth, though, Krugman has since added a post criticizing Clinton for her decision to agree to a debate on Fox News. In this post, titled simply "Stupid," Krugman writes, "Hillary should not agree to debate on Fox News. Fox is part of movement conservatism; no progressive should help it maintain the pretense that it's an objective news organization."