The women say that their professional experiences have led them to an inescapable conclusion: The motives of gargantuan for-profit health care industries — hospitals, pharmaceuticals, insurance — are incompatible with those of health care itself. They argue that a single-payer system, run by the federal government and available to all United States residents regardless of income or employment status, is the only way to fully eliminate the obstacles that routinely prevent doctors and nurses from doing their jobs.

Several proposals now working their way through Congress would aim to create just such a system. The nurses’ support for such proposals — the union has endorsed a bill put forth by Representative Pramila Jayapal of Washington — is somewhat surprising, because the zero-sum nature of American health policy tends to place them on the losing end of any major system overhaul. The money it will take to provide many more services to many more patients will have to come from somewhere, the thinking goes. And the paychecks of doctors and nurses are a likely source.

That calculus has not deterred the nurses.

Perhaps that’s because they see so much time and money wasted by the bureaucracy of the current system. By most estimates, the administrative costs of American health care surpass those of any other developed nation. Or maybe it’s because of the innumerable avoidable medical crises they constantly find themselves confronting. Patients go into heart failure because they can’t afford blood pressure medication, or gamble with their diabetes for want of insulin, then turn up in the hospital needing care that’s far more expensive than any preventive measure would have been.

Or maybe they just know that a steady job with decent health benefits does not exempt anyone from the arbitrary agonies of our current system. Ms. Johnson-Camacho recalls having to discharge a patient without essential chemotherapy — not because the patient was uninsured but because his insurer refused to cover the drug that had been prescribed. “I had just finished explaining to him how important it was to take this medication faithfully,” she says. “I told him, ‘Every day you skip it is a day that the cancer has to potentially spread.’ And then we had to send him home without it.”

Ms. Johnson-Camacho says another patient — a young man with a treatable form of cancer — was so overwhelmed by the cost of his care, and so terrified of burdening his family with that cost, that he told her he was planning to kill himself.