Rural America carried President Trump to his election night upset last November.

Trump Country it may be, but rural counties and small towns also make up Medicaid Country -- those parts of the nation whose low-income children and families are most dependent on the federal-state health insurance program, according to a Georgetown University report released Wednesday.

Medicaid's enrollment has swollen to more than 72 million in recent years, and the ranks of uninsured Americans has fallen to 9% in 2015 from 13% in 2013. That's largely due to the Affordable Care Act, which allowed states to expand Medicaid eligibility with federal funds. Thirty-one states, plus the District of Columbia did so.

Those gains may be in jeopardy under the House GOP health care bill that would replace major parts of the ACA -- known as Obamacare -- and dramatically cut federal funding for Medicaid. The House passed the legislation, the American Health Care Act, in May.

Related: Americans to Congress: Don't touch Medicaid funding

"There is no doubt that children and families in small towns would be disproportionately harmed by cuts to Medicaid," said Joan Alker, executive director of the Georgetown's Center for Children and Families.

Medicaid covered 45% of children and 16% of adults in small towns and rural areas in 2015, according to the center's report. Those figures are lower in metropolitan areas -- 38% of children and 15% of adults.

Rural areas have larger Medicaid populations because more people with disabilities live there, household incomes tend to be lower, unemployment rates higher and jobs with employer-paid insurance less common, the report found.

In states that expanded Medicaid under Obamacare, the rate of uninsured people in small towns and rural areas fell by 11 percentage points between 2008-09 and 2014-15 -- from 22% to 11%, the report said. That was slightly larger than the decrease in metro areas of expansion states.

If the House bill became law, Medicaid would be cut by more than $800 billion over 10 years. That would lead to higher uninsured rates and reduce Americans' access to health care, Alker said.

The Republican-controlled Senate is expected to circulate a preliminary proposal of its repeal-and-replace legislation to members as early as this week. Compared with House members, senators are typically more sensitive to issues facing rural Americans because they represent entire states rather than districts often dominated by urban areas.

With the Senate edging closer to creating its own bill, disability and health advocates and Medicaid enrollees on Tuesday held "Don't Cap My Care" rallies in nine cities imploring Congress to reject efforts to cut Medicaid funding.

About 400 people gathered outside the U.S. Capitol in Washington, D.C. -- blind, disabled, elderly people among them -- with many holding signs reading "Don't Mess With Medicaid" and "No Cuts, No Caps to Medicaid."

Related: Republicans want the poor to work for their government benefits

Ten million people with disabilities rely on Medicaid to help them live, work, attend school and participate in their communities.

Cindy Jennings, a Lititz, Pennsylvania, resident who attended the Washington rally, said she fears the loss of Medicaid coverage under the Republican plan or reduced coverage for her son, Matthew. He is disabled and unable to speak because he was born with a chromosome abnormality.

"It's frustrating and scary," said Jennings, 53. "I need to stay healthy to care for him."

Erickia Bartee said Medicaid enables her to live in a group home and get drugs and other health services to live with cerebral palsy. "I will struggle to survive if my Medicaid benefits are cut," said Bartee, 31, of Owings Mills, Maryland.

Other findings from the report:

-- Thirteen states have at least 20% of adults in rural areas enrolled in Medicaid. Arizona leads the nation with 34% in the program.

-- Rural Oregon saw the biggest gain in adults with insurance over the study's period. Its uninsurance rate dropped 19 percentage points. The share of adults in the state covered by Medicaid increased 17 percentage points.

-- In 14 states, more than half of children in rural areas are covered by Medicaid. Of those, Arkansas and Mississippi were the only states with 60% or more of children in rural areas on Medicaid.

The report defined America's rural areas and small towns as non-metropolitan counties, whose main urban areas have no more than 50,000 people.

Kaiser Health News, a nonprofit health newsroom whose stories appear in news outlets nationwide, is an editorially independent part of the Kaiser Family Foundation.