It's like Moody's. More political than educational. Downgrading the US may be fair, but the main purpose it serves is driving clicks. More to the point, the fact they downgraded the US shouldn't tell the average HN reader anything they don't already know. Contrast to say, S&P.
Edit: By the way, look at the way the top of the "Flawed Democracies" cluster under 8.00! I can totally believe some tweaking went on here.
"Also, seems to be paywalled."
No, it is not. I just downloaded it - even with a Mailinator account.
Why is this post so controversial? The US democracy IS crumbling. And I would have never guessed that I will find this much resentment to this fact in the comments on HN...
Isn't it quite reasonable that it's based on past performance rather than being a guess at what might happen in the future?