it's the faux outrage that's stupid.

The points that Krugman has raised are certainly debatable, which is what we're doing. The problem being complex systems like national healthcare aren't the kind of thing you can just talk your way through, everyone except the experts in the field are just blowing smoke if they definitively claim to have found the "big flaw" no one else has, certainly if they do so without actual empirical evidence to back it up. Anything else is just competing theories, and again, this isn't Krugman's field.

As to the specific points, they were all answered, you just happen to disagree with them. Those who opt will do so because they either 1) can pay but willfully wish to game the system (opt-out means they must actively decide to go this route) or 2) are unable to pay. 1) is dealt with by some sort of penalty when you come back in to make up the loss, as they will inevitably want to at some point (people at the margin who could pay the original but not the penalty will not be effect because this would be known ahead of time and the number who chose to take a small gain to screw themselves later will be minuscule and can't be avoided in any system). 2) Will either be covered by the assistance Sen. Obama would offer to help people meet costs, or would be just as likely to be unable to afford healthcare under Sen. Clinton's system.

How large an issue the people who opt-out (according to the best estimates of the people who know a small percentage) will be we can't know until it happens. Again though, I refer you to Massachusetts, with it's doubled budget and still continued shortfall. Universal healthcare won't be cheap, and it's going to take time to work out all the bugs. We aren't going to have a perfect system on day 1 regardless of what we try.

Your third point is one of the things wrong with Krugman's entire analysis. It's only a problem IF everyone is wrong about how many people opt-out and IF the cost spirals up and then IF the penalties get too high and then only for the miniscule fraction of the population who could afford the original cost but not the cost plus some penalty and who knew this but chose to opt-out anyway and even then only IF there's no plan in place to help defray costs for these people. One might as well ask what about the people who can't afford healthcare under Sen. Clinton's plan, who in turn can't afford the penalties that come from mandates, and decide to move to the slums in Canada to escape. You can sting together infinite chains of ifs to find some miniscule group who might be a problem, but until there's actually numbers and data involved it's just useless tail chasing. Krugman no more knows that this problem will exist than I do it won't, so arguing about it know is just seeing who can yell the loudest longest.