Ohio’s Republican governor, John Kasich, ran for office as a limited-government conservative in 2010 and won. But that did not stop him this month from embracing one of the costliest provisions of President Obama’s health care law — its expansion of state Medicaid. Kasich’s decision, along with those of several putatively conservative Republican governors such as Michigan’s Rick Snyder, Arizona’s Jan Brewer and North Dakota’s Jack Dalrymple, demonstrates how difficult it is to stop the unchecked growth of government.

Obamacare’s expansion of Medicaid has always been one of its most controversial elements. With Medicaid already squeezing state budgets across the country, governors in both parties feared that its expansion to as many as 18 million new beneficiaries would prove unsustainable. After some unpleasant horse-trading over Obamacare in late 2009 (recall the “Cornhusker Kickback”), the bill was changed so that the federal government will pay the whole cost of the expansion until 2020, and then 90 percent of it after that. This will cost federal taxpayers $932 billion over a decade if every state participates, or about 50 percent more than the tax hike on the wealthy that Obama secured at the beginning of this year.