As President Donald J. Trump and the Republican-controlled Congress move to repeal the Affordable Care Act, data in Maryland shows that many of the counties that voted for Trump saw the largest reductions in the ranks of the uninsured under the law.
The biggest drop since enrollment began in 2013 — 11 percent — came in the rural Eastern Shore county of Somerset, according to data provided by the Maryland Health Benefit Exchange, which operates the online marketplace where people can enroll in private insurance and Medicaid.
Somerset was one of 17 counties that voted for Trump over Democrat Hillary Clinton.
The rate of uninsured dropped 10 percent in the Trump-leaning counties of Allegany in Western Maryland and Wicomico on the Eastern Shore.
Baltimore, which went for Clinton, also saw a 10 percent drop.
The rate fell 9 percent in Caroline, Dorchester, Garrett, Washington and Worcester counties, which went for Trump, but also in Baltimore and Prince George's counties, which voted for Clinton.
The law requires people to have health care coverage. It provides subsidies to help low- and moderate-income Americans purchase plans, and assess fines for those who do not have coverage.
Statewide, the uninsured rate dropped 7 percent since 2013.
Other data shows similar results across the country. Analysts at the Kaiser Family Foundation found that among the 11.5 million nationally who enrolled in private Obamacare plans in 2016, 6.3 million lived in Republican congressional districts and 5.2 million live in Democratic districts.
An estimated 20 million people have acquired insurance under the law. In Maryland, more than 430,000 people got coverage this year, according to figures released after the close of open enrollment Jan. 31. Just under 158,000 bought private plans, while 274,000 qualified for the expanded Medicaid, the federal-state health program for low-income people.
A few nuanced reasons likely explain why the state's Republican counties saw greater gains from Obamacare, said Cynthia Cox, associate director of health reform and private insurance for Kaiser.
In Maryland, more people voted for Clinton, but more counties went for Trump, and they were more likely to be rural. People in those counties were more likely to work for small businesses or farms, she said, and might not get insurance from their employers. That would push more into exchange-based coverage.
Nationally, red-state politics might have played a role in boosting participation in private plans. Some states governed by Republicans did not expand Medicaid, forcing more residents to buy policies on the exchange or pay the penalty.
Some voters might have embraced Trump because he promised to repeal and replace Obamacare, Cox said.
"The biggest concern for people is cost," she said. "And a lot of people who voted for Trump may have really expected they'd get a better deal."