Capitol Hill Republicans are not surprised by a new study that suggests more people will make emergency room visits under ObamaCare, not fewer as President Obama and other supporters of the law argue.

The Harvard University study recently published in the journal Science shows that emergency room visits increased by 40 percent for those who received Medicaid when Oregon expanded the program in 2008.

“While these higher costs don’t come as a surprise to many, it has left us wondering why do Democrats call it the Affordable Care Act if the law doesn’t lower the cost of heath care,” said Michigan Republican Rep. Dave Camp, chairman of the House Ways and Means Committee.

Roughly 2.1 million Americans have enrolled in ObamaCare since signups started in October, as the administration aims to eventually get health insurance to about 25 million Americans by 2016. And roughly half of those will be covered through Medicaid expansion.

The president has touted his signature law since introducing it in 2007 as a means of saving Americans money.

ObamaCare would save taxpayers money, he and supporters argue, by getting the previously uninsured to make doctor visits through coverage plans instead of making uncovered emergency room visits.

The president even argued the point as recently as November to a crowd in Dallas while pitching ObamaCare.

“All the providers around here, instead of having to take in folks in the emergency room, they suddenly have customers who have insurance,” the president said.  “That means those of you who already have health insurance, your premiums will not be subsidizing folks who don't have health insurance.”

The Harvard study followed the emergency room use of 25,000 low-income Oregon adults who received Medicaid through a lottery.

The randomized study tracked the recipients in their first 18 months of coverage, and the findings were based on emergency-department records from Portland-area hospitals.

Study authors said they found Medicaid coverage significantly increases overall emergency use by 40 percent, compared to an average of 1.02 visits a person in the control group.

They also found an increase in emergency-department visits “across a broad range of types of visits, conditions and subgroups” including increases in visits for conditions that may be most readily treatable in primary care settings.

Administration spokeswoman Tara McGuinness told The New York Times that the length of study was too short to expect much change in the habits of people who get insurance and pointed to a years-long study in Massachusetts that found an 8 percent decrease in emergency department visits.

“Medicaid saves lives and improves health outcomes,” she said. “Plenty of studies show that.

Jonathan Gruber, a Massachusetts Institute of Technology health economist and Affordable Care Act adviser, told The Washington Post the study shows health-care expansion will not save money through channeling Americans away from emergency room visits.

"I would view it as part of a broader set of evidence that covering people with health insurance doesn't save money," he told the newspaper. "That was sometimes a misleading motivator for the Affordable Care Act. The law isn't designed to save money. It's designed to improve health, and that's going to cost money."