SPEAKER PAUL D. RYAN (R-Wis.) said Thursday that the House would consider a new Obamacare replacement bill “when we have the votes.” Given the legislation that’s being drafted, that ought to be never. Any politician who pledged to protect people with preexisting conditions would betray that promise by supporting this bill.

The amended American Health Care Act (AHCA) is much the same as the old repeal and replace, which the Congressional Budget Office found would erode insurance plan quality and push 24 million off coverage. But this version also would allow states to rescind some of Obamacare’s central protections, most notably that insurance companies cannot charge sick people more than healthy ones. This “community rating” provision is at the core of Obamacare’s guarantee of meaningful access to health-care coverage to people with preexisting conditions.

“There is no question that the amendment to the AHCA lets states end guaranteed access to insurance for people with pre-existing conditions,” the Kaiser Family Foundation’s Larry Levitt tweeted Thursday. “Insurers would be required to offer insurance to people with pre-existing conditions, but could charge them unlimited premiums.”

States that wanted to revoke these protections would create high-risk pools for sick insurance-buyers or establish reinsurance programs that would help insurers defray large medical costs. But federal grants would provide “nowhere near enough . . . to address the needs,” Linda Blumberg, a health economist at the nonpartisan Urban Institute, wrote in an email. Even if they did, “the AHCA includes no requirements for high-risk pool eligibility, premiums, or benefits,” Mr. Levitt explained. “So, there is no guarantee for people who are sick.” Reinsurance programs could be even worse: Ms. Blumberg explained that reinsurance “could lower premiums for those that are buying at ‘standard’ rates, but it might do absolutely nothing to make coverage affordable for those that are sick and rated up.”

Coverage among the young and healthy might increase, since insurers free to pick and choose their customers would set low, attractive premiums for people who do not need much care and prohibitively high premiums for people who do. Mr. Levitt predicts that the result might be somewhat more people covered than the original AHCA’s abysmal numbers. Or, Ms. Blumberg argues, the amendment could still increase the number of uninsured by forcing more sick people out of the system.

Either way, looking simply at the number of uninsured underestimates the misery this policy would cause. Replacing sick people with healthy people on the insurance rolls means less help for those who really need it.

The bill has the support of the hard-right Freedom Caucus and at least one prominent House centrist, Tom MacArthur (R-N.J.), putting the responsibility on others to halt it. As of Thursday afternoon, nearly enough had said they oppose the new bill, though the GOP’s centrists could be in for some intense arm-twisting.

The bill is breathtakingly unpopular, as is the whole repeal-and-replace effort, and deservedly so. Do Republicans really want to risk their House majority for this?