WASHINGTON ― President Barack Obama’s top health official predicted Tuesday that Republicans will back off from repealing the Affordable Care Act as more people realize what the consequences would be.

The Congressional Budget Office became the latest independent entity to spell out those consequences in a report issued Tuesday. The “repeal and delay” plan favored by congressional GOP leaders ― in which an Obamacare repeal bill would quickly be passed, with a “replacement” following as much as four years later ― would wreak havoc on the health insurance market. The results would include 18 million people losing their coverage and rate hikes that could exceed 20 percent next year, and millions more losing coverage in later years.

“Repeal and delayed replacement is repeal,” Health and Human Services Secretary Sylvia Burwell said at a briefing with reporters. “I believe that when faced with this kind of impact, that that’s not what people came here to do, and so there will be a different trajectory.”

“In the time since the election, we have shifted, and we are starting to see that movement from rhetoric to reality in terms of the conversation around the Affordable Care Act,” Burwell said, noting the public backlash to Obamacare repeal and the uncertainty among members of Congress on how and when to move forward with keeping the GOP’s promise to undo Obama’s health law.

An NBC News/Wall Street Journal survey released Tuesday found the health law has never been more popular and that nearly half of Americans doubt the GOP’s ability to do better.

Repeal and delayed replacement is repeal. Health and Human Services Secretary Sylvia Burwell

Citing the CBO findings, Burwell predicted that passing an Obamacare repeal bill but leaving most of the law in place for a year or more before different health care reform gets enacted would severely damage the health care system in the short term.

Health insurance companies would pull out of the market, in some cases leaving consumers with literally nowhere to buy policies.

Reduced competition also would contribute to rapid increases in premiums, which would make insurance unaffordable for many, leading them to go without coverage. Those with the greatest, and costliest, health care needs would be most motivated to maintain their insurance, which would drive up costs for the customers who remained in the market.

Those later price increases would push even more people out of the market, leaving an increasingly sick and expensive pool of customers.

In insurance parlance, that cycle is called a “death spiral.” Burwell demurred on whether that term would apply under the scenario analyzed by the Congressional Budget Office, but still issued a warning: “I think it is fair to say that it puts the marketplace in that kind of a negative spiral.”

We actually really haven’t seen a plan. An outline is not a plan. Health and Human Services Secretary Sylvia Burwell

Burwell, who said she’d had no contact with President-elect Donald Trump’s transition team in weeks, also emphasized that it’s impossible to evaluate how any Republican “replacement” plan would work because there isn’t one.

Trump, House Speaker Paul Ryan (R-Wis.) and other Republicans ― including Rep. Tom Price (Ga.), whom Trump has tapped to take over for Burwell ― all tout competing plans, most of which have never been made into legislation that could actually be analyzed.

“We actually really haven’t seen a plan. An outline is not a plan. A framework is not a plan,” Burwell said. “The fundamental question here is: What do you want this to look like? What do you want health care in the United States to look like? And that’s the question that time and time again is going to have to be answered.”

Future health care reform proposals will need to be measured on three counts, Burwell said: whether they increase the number of people with coverage and access to care; whether that coverage is more affordable; and whether the insurance actually provides comprehensive benefits.

The current open enrollment period for policies sold on the Affordable Care Act’s health insurance exchanges, such as HealthCare.gov and Covered California, ends Jan. 31, three weeks after Burwell leaves office and the Trump administration takes over.

A key component of Republican messaging on their “repeal and replace” strategy is portraying the exchanges as so broken, dismantling the law is the only way to fix the health insurance market.

But enrollment is currently outpacing last year’s, if modestly, and the financial condition of the exchanges is improving, putting that talking point at odds with the emerging evidence, Burwell said.

Burwell herself soon will learn firsthand how the Obamacare market works for consumers. When her federal health benefits go away this Friday, she and her husband ― who survived cancer and thus has a pre-existing condition that could have excluded him from coverage before the Affordable Care Act ― will be shopping for coverage on the District of Columbia’s exchange, DC Health Link, she said.