Paul Krugman applauds the Senate health care bill for, among other things, forcing insurance companies to cover patients with pre-existing conditions. This has been a long standing point of reform: why should a family be forced to cover the expenses of a medical problem when they had no role to play in the development of the condition. It's not as if they're smokers suffering from lung cancer. And many families can't afford the very expensive treatments that come with such conditions. But insurance companies can and so, the argument goes, they should pay.
For one, I'm not sure they can, but there's a deeper point. A pre-existing condition is tragic, doubly so if burdened on a family who cannot afford to properly address the issue. But that does not translate into forcing someone else to shoulder the burden, whether the target is insurance companies, hospitals, or the U.S. government (though the last is most justified since, in theory, it works for all of us). Some believe that doesn't matter; covering such individuals is the right thing to do. But that misses the larger picture. Even if they could afford it and even if they could continue to afford it for the foreseeable future, it would be ethically wrong to force one group to shoulder the problems of another group. Yes, I know we do this a lot already, but that's hardly grounds to keep doing it.
Here's an analogy. Some people are born ugly, or stupid, or socially awkward. Such people have difficulty getting dates or maintaining friendship. While befriending a person with such a pre-existing condition just to be nice would be seen as an admirable act of kindness, no one would agree to a policy which forces people to befriend or date such individuals. It would be seen as unethical, even if the individual is not able to "afford" such loneliness (i.e. they are suicidal).
It's all well an good to ask for things but you have to think about where they come from.