The nation’s uninsured rate has dropped about 5.2 percentage points since the Affordable Care Act (ACA) went into effect, though that number stayed relatively stagnant last year as some GOP-dominated state legislatures and Republican governors have stalled Medicaid expansion.

The rate was 11.9 percent at the end of 2015, about the same as it was at the beginning of the year, according to the Gallup-Healthways Well-Being Index released Thursday.

The new data comes a day after the Republican-majority House sent a bill to President Obama’s desk that would repeal major provisions of the ACA. Obama has said he will veto the bill, which, among other provisions, eliminates tax penalties for the uninsured and cuts federal funding to Planned Parenthood. Many opponents of expanding health-care access hope the bill will keep it a key talking point throughout the 2016 presidential election.

But many Democrats believe that the Republican-backed bill alienates the key voter groups that benefit from Obamacare.

“It’s 2016 and House Republicans are still tightly bound to their old, failed playbook, which not only puts the health of millions of Americans at risk, but also threatens Republicans’ standing with women, Latinos and other important groups of voters this election year,” Rep. Ben Ray Lujan (D-NM), the Chair of the House Democrats’ campaign committee, told CNN.

All major demographic groups, except seniors, have experienced gains in insurance coverage since the law was passed. The biggest drop in uninsured rates have come among Latinos, Black people, and low-income people, according to Gallup.

One way the ACA has been successful in reducing the uninsured rate is allowing states to opt for a Medicaid expansion aimed at low-income adults with no children living at home.

But many states with Republican-dominated legislatures have chosen not to expand Medicaid. Texas, Florida, Georgia, North Carolina, and Virginia are all highly populated states that fall into that category. If they expanded Medicaid, the uninsured rate could see a major decline. Many Democrats and Obama administration officials believe GOP lawmakers are more interested in seeing the law fail than they are in expanding access to health care.

“As I travel the country, I consistently hear Americans say that they want Washington to build on the progress we have made to increase access to coverage, drive down the growth of health costs and improve the quality of care,” Health and Human Services Secretary Sylvia Burwell said in a statement after the House approved the measure to repeal parts of the health-care law. “Unfortunately, today’s partisan effort in the House of Representatives to repeal key parts of the ACA, along with its effective defunding of Planned Parenthood, does the opposite.”

Burwell said in her statement that there was an unprecedented demand for coverage under open enrollment for 2016, and some states are reporting increased enrollment over last year.

The uninsured still have a few weeks to sign up for insurance coverage and avoid paying the penalty for going without insurance, which for 2016 is $695 per adult, or 2.5 percent of household income, whichever is greater. Many in the United States will opt for the penalties, saying those fees amount to less than an insurance plan would under the ACA. The deadline to enroll is January 31.