The Supreme Court’s ruling last month that the states should have the choice of whether to expand their Medicaid programs has set the stage for a frenzied year and a half in which governors will have to analyze their options, devise plans, negotiate with the federal government and successfully navigate the thorny statehouse politics that often accompany any big change. Much of the law is set to take effect in 2014, when many governors will be facing re-election.

The initial reaction to the court’s ruling split along party lines. More than half a dozen Republican governors — including those of Texas and Florida, which have the nation’s largest populations of poor uninsured residents — said they would not expand their programs because Medicaid already eats up an unsustainable share of their budgets. A slightly bigger number of Democratic governors said they would move swiftly to expand coverage in their states, with the federal government pledging to pick up all the costs at first and 90 percent of them after 2020. …

Gov. Bob McDonnell of Virginia, the chairman of the Republican Governors Association, has been one of the sharpest critics of the health care law, but he did not rule out the possibility that he might ultimately decide to expand his state’s Medicaid program. “Honestly, I don’t think it’s responsible for my state, fully, to make the decision now,” he said.