The more muddled Barack Obama’s crusade to remake US healthcare has become, the higher share prices of big insurers such as UnitedHealth, Aetna and Humana have risen. They faltered this week as plans emerged from the Senate to directly tax the industry to help pay for coverage to nearly 50m uninsured Americans.

The main distinction between soaking insurers directly and eliminating the tax-free nature of employer health benefits is that the latter proved wildly unpopular, particularly among Democrats’ union allies, while the former is palatable to all but insurers’ shareholders. But the distinction would rob Peter to pay Paul as both would result in higher customer outlays or more limited coverage for those already insured.