Krugman's reputation as a partisan hack that opines on matter he is ignorant about is among other economists with no fewer accomplishments (but his reputation as a pompous ass is among everyone else).
People treat Google the same way every time some Labs experiment like Wave fails. They think it means Google's lost their Edge and spinning their wheels. It's equal-and-opposite pessimism to go with the optimism.
This is why I do not treat your counterexamples to Silver's accuracy as a convincing slate of proofs. I don't have enough context to judge those failures against the background of his success or vice versa.
I do find Nate Silver interesting not just for his psychic abilities. He also brings a certain love of statistics and visualization that deserves the level of coverage he gets. Is he doing any better predicting than some quant or world-class stat guy? No, and you can probably find someone who has a better combination of predictions and historical accidents. But he's also bringing the science to the populace, and that is worth praising and talking about.
I do find this 2005 (!) opinion piece by Krugman calling the housing bubble to be an interesting datapoint.
http://www.nytimes.com/2005/08/08/opinion/08krugman.html
But between the Silver stuff and the Krugman stuff I do feel like I have enough context to judge that you have your own axe to grind.
It's like if you're congratulating Steve Jobs on a successful iPad launch. You aren't obligated to also mention all of the products he has worked on that haven't done so well.
And I hardly doubt anyone was trying to convince you, or any other reader on HN, that Nate may have mispredicted something. In fact, I'm going to go out on a limb and say that there is no one on this planet who has not made a false prediction.
But since you're so adamant about this, could you put together a list of his complete record with links?
And sure, Krugman has a Nobel Prize, Clark Medal, Ivy League tenured job, nominated for a Pulitzer, but he'll have to live with spec calling him a partisan hack.
I'm not sure anyone would mind that tradeoff.