I have been asked by two people today about Paul Krugman and why he is continuing to attack Barack Obama. I don't want to get into the details of the accusations, there's been enough on that, but I do want to offer an explanation by making a couple of points about the strategy.
First, Paul Krugman has been researching and writing about health care for a long time and he cares deeply about health care reform. It's one of the issues that has dominated his column for a long, long time. He sees an opportunity like we have never had before to make fundamental changes to the system that will increase its availability, help to control costs, and so on, and he does not want to see that opportunity lost.
One way to respond to worries that Obama won't push hard enough for health care reform if he is elected is to force him to take strong positions now, to bait him into promising that he will in fact pursue this issue. You say, if you are someone people listen to, something like "I don't think Obama is very serious about health care reform." When he or his spokespeople respond that he is too serious, he cares as much as Hillary or anyone else, just you wait and see, you have forced him into a position that will be much harder to back down from in the future. And that is the point. Make him clarify his position now, then hold him to it (and stop him from saying things that will make it harder to pursue reform when the time comes).
Second, it's important to think about who the audience is for his columns. Most people who read Krugman don't do it at the NY Times website, and they don't read every column, follow his blog, read his books, and so on. Not even close. If you aren't an economist or a political junkie, you may not even know who he is (my parents don't have a clue - they get Krugman mixed up with Kagan which is funny, not ha ha funny though). Most people read the morning paper and if the column is there, they (may) read it. If not, they never see it. He has indirect influence on the political dialogue, and that may affect what they hear, but his direct line to them relies upon his column being syndicated, then read.
My local paper does not print every column. I have no idea how many they print (1 out of 5?), but it's probably less than you think. So the syndication audience reads far less of what Krugman writes than most of us. Thus, you'll see him repeat the Bush quote “I mean, people have access to health care in America. After all, you just go to an emergency room.” in many columns, I think it even appeared in consecutive columns. If you read everything he writes, it might seem repetitive and naggish, but that's because you are not a typical reader. The typical reader - even with all the repetition - may not see it at all. So when it appears that he is going after something or someone in column after column, doggedly pursuing an issue, when he is being shrill so that his voice stands above the rest and catches people's attention, I think it's important to interpret it in this light.