For the second time in two years, Congress is about to abandon millions of Americans who depend on community health care. And President Donald Trump, who has reason to pay special attention to these patients, seems willing to let it happen.

The $4 billion Community Health Center Fund, which was created almost a decade ago by the Affordable Care Act, helps to pay for the operations of nearly 1,400 community health centers serving some 28 million Americans. If Congress fails to pass a permanent spending bill by Nov. 21, one month from today, these centers will be forced to scramble for funds, and the message will be clear: These clinics, and the people they serve, are expendable.

This has happened before. During budget negotiations in late 2017 and early 2018, there was a five-month funding lapse. More than half of community health clinics considered laying off staff and a third considered reducing services, according to a survey by the Kaiser Family Foundation. More important, millions of the most vulnerable Americans were forced to deal with uncertainty about their health care.

Those who rely on community health centers tend to be less able to travel farther or adjust their schedule if a clinic reduces hours or closes. An estimated one in four community health center patients are uninsured, one in six have government insurance for low-income Americans (Medicaid or the Children's Health Insurance Program), and 10% are children.

Community health centers, which are open to everyone regardless of ability to pay, provide basic care in areas designated as underserved by the federal government, which provides one-fifth of all health-center revenue. Those federal dollars are disproportionately important to centers in red states. In 12 states — 10 of which voted for Trump in 2016 — federal funding makes up at least 30 percent of their revenue.

The fund was included in the continuing resolution budget passed by Congress and signed by the president last month. But with congressional time and attention turning to impeachment proceedings, securing permanent funding could be difficult. This puts community health centers in limbo yet again.

These clinics are on the front lines, caring for vulnerable patients in areas with few other health-care options. Centers screen for STDs, ensure that expectant mothers get proper prenatal care and, in some cases, offer treatment for opioid addiction. These services are especially vital in states that didn't expand Medicaid, which both rely more heavily on federal grants and have more patients without insurance.

Congress is known for its dysfunction these days, but it has been able to agree on some things, such as a $4.5 billion humanitarian and technical aid package for the U.S.-Mexico border in July.

Public health deserves the same kind of focus and action. Funding these centers, which are in both urban and rural areas, shouldn't be controversial: The program has historically had bipartisan support. All it takes is for Congress to make it a priority.

Mattie Quinn, a former reporter for Governing magazine, is a writer and journalist focused on health care and the social safety net.