Republicans have demonized the Affordable Care Act for so long that people may have forgotten that nearly one in five nonelderly Americans lacked health insurance before the law was passed. Many of them didn’t get the care they needed because they feared it would bankrupt their families. The A.C.A., or Obamacare, has not solved those problems completely, but it has extended health care coverage to 20 million people.

The Republican health care bill under consideration in the Senate would undo that progress and make the health care system even worse than it was before Obamacare. In May, the House passed its version of the legislation, the American Health Care Act, which would take insurance away from 23 million people, according to the Congressional Budget Office. At the same time, the bill would lavish tax cuts on the wealthiest families. So it is no surprise that about 55 percent of voters oppose the Republican effort to replace the A.C.A., while 30 percent support it. Undeterred by the public’s wishes, by compassion or by common sense, President Trump and other Republican leaders are forging ahead.

We asked Times readers how the Republican proposals would affect them. Here are a few of their stories. Lawmakers should know that there are many more Americans like them who are worrying about a future without affordable health care.