As a political matter, it’s easy to see how a bill to assert the Legislature’s responsibility for any expansion of Medicaid under Obamacare provides fodder for Democrats.

As a practical matter, though, it’s hard to see how it amounts to the kind of change that has liberals howling.

House Bill 990, which has the backing of that chamber’s top leaders, would require the General Assembly’s approval for any expansion of Medicaid eligibility. Currently, the decision rests — only nominally, as we’ll see — with the governor.

Expanding Medicaid was a key component of Obamacare. But in 2012, the Supreme Court ruled it was up to states to decide whether to cover people earning up to 138 percent of the federal poverty level. This year, that threshold comes to about $16,100 for a single person or $32,900 for a family of four.

A couple of months after the court’s ruling, Gov. Nathan Deal said he would not expand Medicaid. He cited the rapidly rising costs of Georgia’s current Medicaid program, the high cost of paying the state’s share of an expansion, and the probability the federal government wouldn’t live up to its promise to pay 90 percent of the costs in perpetuity. He indicated Georgia might be able to cover more people if it had more flexibility to run Medicaid as it sees fit, as GOP members of Congress including Paul Ryan have proposed. All of which is sound reasoning.

There are other arguments against expansion. Medicaid's low reimbursement rates have led some doctors not to accept new Medicaid patients, limiting how much new access to health care, as opposed to merely health insurance, an expansion would really provide.

What’s more, an important study looking at Oregon’s 2008 expansion of Medicaid found new recipients were more, not less, likely to make costly trips to the emergency room for non-emergencies. That finding undermines a key expansionist claim that putting more people on Medicaid would reduce health spending elsewhere.

Speaking of money, let’s get back to HB 990. Deal has argued the Obamacare expansion of Medicaid would cost Georgia an additional $4.5 billion over 10 years. Expansion proponents claim the number would be about half as much. Either way, we’re talking about at least a couple of hundred million dollars a year.

Who can appropriate that kind of money? Not the governor; not on his own.

There is no secret stack of money under the mattresses on West Paces Ferry the governor can grab to spend an additional $325 million on Medicaid or anything else. Legislators have to approve it.

Nathan Deal, or for that matter his Democratic challenger Jason Carter, could sign all the Obama-esque executive orders he wants. The Legislature holds the power of the purse and therefore already has a very large say in whether Medicaid is expanded. Do Democrats really believe the legislative branch should abdicate that responsibility?

There is a short window of opportunity for the governor to expand Medicaid without additional state spending. For the first three years of the expansion, the federal government pledges to pay the full cost, with the state picking up a growing share of the tab afterward.

But it’s beyond naive to believe state legislators would be truly free to withhold funding after that, as the tab grew to hundreds of millions of dollars a year. Why should the governor and the president be able to bind future state legislatures in such a way, without any agreement from even the current General Assembly?

As long as Georgia and other states hold out on an expansion, there is at least some pressure on Congress and the White House to consider improvements to Medicaid. If experiments such as paying providers a flat fee to care for patients (known as “capitation”) rather than reimbursing them for each procedure (“fee for service”) prove beneficial, states might cover more patients for the same amount of money, or at least reduce the marginal cost of covering them to an acceptable level.

Until then, it’s entirely appropriate the Legislature make clear its role in deciding how taxpayer money is spent.