Bluntly, it means more severe injuries and death.

Many of the same people who protest against "trading blood for oil" when it comes to military interventions in the Middle East seem not to see that higher miles per gallon can also mean trading blood for oil.

The magic number du jour is the number of Americans without health insurance. Apparently getting more people insured is another "good thing"-- which is to say, it is something whose costs are not to be weighed against the benefits, or whose costs are to be finessed aside with optimistic projections or a claim that these costs can be covered by eliminating "waste, fraud and abuse."

In real life, people weigh one thing against another. But in politics one declares one thing to be imperative, so the issue then becomes how we do it. In real life, all sorts of desirable things are not done, either because of other desirable things that would have to be sacrificed to do it or because of the dangers incurred .