A major new study finding that expanding Medicaid does not improve the physical health of the program's beneficiaries is embarrassing for Republican governors who backed Obamacare's expansion of Medicaid.

To recap, last year's decision by the U.S. Supreme Court gave states the option of not participating in a vast expansion of Medicaid that could cost the federal government around $1 trillion over the next decade if all states participate.

However, in recent months, a group of Republican governors who supposedly support a less-intrusive role for government routinely employed liberal rhetoric in making their case for expanding Medicaid, which provides health insurance to low-income Americans.

"I cannot in good conscience deny the uninsured access to care," Florida Gov. Rick Scott said in explaining why he had reversed his previous position on Medicaid expansion. Of a scenario in which Medicaid wasn't expanded, Arizona Gov. Jan Brewer said, "The human cost of this tragedy can't be calculated."

Michigan Gov. Rick Snyder declared, "This makes sense for the physical and fiscal health of Michigan." New Jersey Gov. Chris Christie said it was the "smart thing to do for our fiscal and public health." New Mexico Gov. Susana Martinez said, "We have an obligation to provide an adequate level of basic health care services for those most in need in our state."

Ohio Gov. John Kasich laid it on particularly thick. "They can't afford health care," Kasich said of the uninsured. "What are we going to do, leave them out in the street, walk away from them when we have a chance to help them? The program provides a pathway for these individuals to get basic health care from a doctor." Otherwise, he argued, "it's not fair for them because they don't get healthier, so they're sicker and we pay for that as well."

Other Republican governors who decided to expand Medicaid were Nevada Gov. Brian Sandoval and North Dakota Gov. Jack Dalrymple.

In Florida, Ohio, Michigan and Arizona, Republican legislators have smartly resisted efforts to expand Medicaid. And their skepticism was vindicated by a scientifically rigorous new study that undercuts the assumptions perpetuated by the Medicaid-promoting Republican state executives.

The study, released last week in the New England Journal of Medicine, looked at the impact, after two years, of Oregon's decision to expand Medicaid in 2008. Because the state didn't have enough funding to expand the program to everybody who wanted to apply, lawmakers held a lottery for potential applicants.

This provided a unique opportunity for researchers to compare a random sample of 6,387 low-income adults who were able to enroll in the program with 5,842 who were not selected. Researchers found that those who enrolled in Medicaid spent a lot more on medical care than those who weren't able to enroll, but didn't significantly improve their health physical outcomes.

The results also undercut another argument being advanced by Republican governors -- that insuring more people would cut down on costly emergency room visits.

The Oregon study "did not find significant changes in visits to the emergency department or hospital admissions" when comparing the uninsured population to those who received Medicaid.

Over the next decade, governments at all levels are projected to spend $7.4 trillion on Medicaid, according to the Kaiser Family Foundation. According to the National Association of State Budget Officers, the program gobbles up nearly one out of four dollars of state budgets, more than any other single program. This means that other priorities, such as education and transportation funding, must routinely get sacrificed to subsidize Medicaid.

Republican governors supporting expanding Medicaid are trying to argue that it is the humane thing to do. But there is nothing humane about taking money from middle class taxpayers to finance a health-care entitlement for the poor that, according to the best available research, does not improve their health.

Philip Klein (pklein@washingtonexaminer.com) is a senior editorial writer for The Washington Examiner. Follow him on Twitter at @philipaklein.