At a health-care forum last week, for example, White House budget director Mick Mulvaney agreed that America should provide a safety net for those with natural conditions, "so that if you get cancer you don't end up broke." Then he added: "That doesn't mean we should take care of the person who sits at home, eats poorly and gets diabetes. Is that the same thing as Jimmy Kimmel's kid? I don't think that it is."

It's not a new argument, nor is Mulvaney the first to raise it. But it is not very persuasive. For one thing, it disregards the concept of insurance — which holds that the healthy share in the cost of care for the sick in return for the security of knowing they'll be covered, too, when the time comes.

More important, the argument creates an artificial distinction between people who need medical care through no fault of their own and those who are somehow responsible for their condition. Yes, there are cases that can be considered acts of nature, such as a heart defect at birth. But most illnesses — including diabetes, heart disease, and even lung cancer — arise from the interaction between genetics and behavior.

Mulvaney and other defenders of the AHCA seem not to have worked through the implications of their argument. If they did, they might have inserted language into the bill to distinguish the undeserving sick from the deserving. Such a provision would be impossible to write, of course — and difficult to enforce, not to mention cruel — so the AHCA simply puts health insurance out of reach for all sick people if they let their coverage lapse for two months.

It may well be that Republicans decide their bill needn't pass the Jimmy Kimmel test — maybe they think it's too expensive, or have other priorities. If that's the case, then they should say so. Otherwise, their arguments fail a basic test of integrity.