Now that the essential Republican plan for healthcare is being implemented nationally, health insurance companies are jubilant.

Last week, after the giant insurer Wellpoint raised its earnings estimates, CEO Joseph Swedish pointed to “the long-term membership growth opportunity through exchanges.” Other major health plans are equally bullish. “The emergence of public exchanges, private exchanges, Medicaid expansions … have the potential to create new opportunities for us to grow and serve in new ways,” UnitedHealth Group CEO Stephen J. Hemsley effused.

So why are today’s Republicans so upset with an Act they designed and their patrons adore? Because it’s the signature achievement of the Obama administration.

There’s a deep irony to all this. Had Democrats stuck to the original Democratic vision and built comprehensive health insurance on Social Security and Medicare, it would have been cheaper, simpler, and more widely accepted by the public. And Republicans would be hollering anyway.