Updated on December 2 at 1:30 p.m.

Don’t be so quick to kiss Obamacare goodbye.

Yes, the election of Donald Trump and Republican majorities in Congress will in all likelihood signal the death knell for the Affordable Care Act—eventually. But as Republicans confront the complexity in policy and politics of replacing the law, they are leaning toward a strategy that would actually leave it on the books for as many as three more years.

Conservatives in the House have been touting the plan since the first days after the election, and it was confirmed by Senator John Cornyn of Texas, the second-ranking Republican, in an interview with Politico. It goes like this: The House and Senate would repeal most, though not all, of Obamacare with simple majority votes in January as soon as Trump takes office, but they would set the date of enactment starting in 2019 or even 2020. The delay would allow for a semi-orderly transition for the health insurance market, and it would buy time for Republicans to coalesce around a replacement package and—they hope—persuade at least eight Senate Democrats to cross party lines, break a filibuster, and pass it into law.

This is a potentially perilous strategy for several reasons, each of which illustrate why overhauling an industry that comprises one-fifth of the American economy is an enormously difficult task.

The Politics of Repeal Itself

The Affordable Care Act has been unpopular for most of its brief existence, but the idea of repealing it has always been even less popular. That continues to be the case even after the November election. A poll released Thursday by the Kaiser Family Foundation found that just one-in-four Americans support full repeal. Another 17 percent want the law scaled back, while a higher percentage want lawmakers to either make no changes or expand it. An often overlooked dynamic in health care polling is that a big part of the opposition to Obamacare has come from people who believe it did not go far enough to begin with. Those same people think repealing it entirely would make the system worse.

So Republicans will be going against public opinion when they vote to scrap the law early next year. But they will do so anyway because their conservative base demands it, and because they will never be as unified as they are in the immediate, heady aftermath of their electoral victory.

Still, there is no guarantee that Republicans will even have enough votes to repeal most of Obamacare without a replacement ready. The party’s majority is comfortable in the House, but not the Senate. The GOP is likely to have 52 Senate seats come January, assuming its nominee, John Neely Kennedy, wins a runoff election in deep-red Louisiana later this month. A budget procedure known as reconciliation allows Republicans to repeal most of the law with a simple majority—50 votes plus the vice president. Some consumer protections, including the ban on insurers discriminating based on pre-existing conditions, would likely have to stay in place.

Can they pass it with such a slim margin? Probably, but there are already two question marks. One is Senator Susan Collins of Maine, the centrist Republican who voted against repeal in late 2015. The bill she opposed then is likely to be similar if not the exact same one that comes up in January. Asked on Thursday how she might vote if the measure came up again, Collins did not answer directly. Instead, she issued a two-paragraph statement on the law that made no mention of repeal. “Under the incoming administration, Republicans and Democrats have a new opportunity to fix Obamacare, and there is a lot to fix,” she said. Collins cited the problem of rising premiums but also noted the consumer-protection provisions of Obamacare that, she said, “enjoy widespread support.”

Many of my colleagues have ideas about ways to reform health care, myself included.  I look forward to evaluating all legislative reform proposals introduced in the new Congress to increase the availability of affordable, quality health care for millions of Americans.

A spokeswoman for Collins, Annie Clark, followed up after this article was published to note that the Maine senator had voted against the repeal bill in 2015 because it also defunded Planned Parenthood. “Senator Collins has long supported the effort to repeal and replace,” Clark said. She added that Collins would have to see the specifics of the repeal bill next year before deciding how to vote on it.

The other potential problem is Senator Lamar Alexander, who as chairman of the Senate Health, Education, Labor, and Pensions Committee, will have a lot to say about the repeal effort. Alexander voted for repeal last year, but in recent days he has made clear that he prefers a different strategy for ending the ACA: “replace and then repeal.”

Explaining his position, Alexander cited Trump’s interview on 60 Minutes, where he promised there would be no gap between the exit of Obamacare and the arrival of its replacement. In a statement on Thursday, he said he wanted repeal to occur in stages:

Immediately in January, Congress and the administration can begin to repeal Obamacare and provide relief from the Obamacare emergency. And as President-elect Trump has said, Congress should replace and repeal at the same time, which requires figuring out how to replace it before fully repealing it. To avoid the historic mistakes of Obamacare, that replacement should be implemented step-by-step to minimize disruptions and make sure the changes in the system work well. Conservatives especially know that a comprehensive health care solution—even a Republican one—for a country of 320 million people in 50 states won’t work.

The Problems With Delay

In theory, the delayed death strategy seems reasonable, even responsible. Republicans don’t want to throw 20 million people off their health insurance if they can avoid it, and even the most ardent critics of the Affordable Care Act understand that a transition period is needed. “That gives us time to put the replacement in place and not just strip the rug out from under people,” said Representative Steve King of Iowa, who has been fighting Obamacare since its inception. “We need to give people confidence that we’re planning for that.”

In practice, however, delay could be a disaster. Insurers have already been leaving the Obamacare exchanges, leading to fewer options and higher-priced plans for shoppers. Repealing the law could cause a further exodus long before the measure takes effect. As Robert Laszewski, the president of Health Policy and Strategy Associates, told Vox’s Sarah Kliff: “The problem is when you have an insurance market, and the new administration declares it DOA, it will go into death throes.” Laszewski and other industry experts have said that Congress could mitigate the fallout by temporarily increasing subsidies for insurance companies, but that is exactly the kind of policy that Republicans derided as a “bailout” and successfully killed a couple of years ago.

The Challenge of a Replacement

There’s a reason the Republican Party hasn’t been able to agree on a single, comprehensive legislative alternative to Obamacare in the last six years: Conservatives are divided on the details, health policy is incredibly complex, and the plans they have come up with will be difficult to sell to the public—especially once Democrats start highlighting the many people who will lose Medicaid coverage or face higher costs as a result. Recall that Democrats only barely passed the Affordable Care Act in 2010 when they had 59 seats in the Senate, or seven more than the GOP will control next year.

Republicans, including Trump, have said for example that they want to keep the popular provisions of Obamacare covering people with preexisting conditions and adult children included in their parents’ plans. But those consumer protections only work economically in tandem with the many other policies embedded in the Affordable Care Act that allow insurance companies to pay for sick people while still making a profit. One of those is the mandate that all individuals buy insurance, which Republicans will surely ax.

Politically, Republicans need the delay, because unless they get really creative with the budget reconciliation process, they will require 60 Senate votes—not 51—to pass a new health law. That means they’ll need a group of Democrats to join them, and party leaders believe, or at least hope, that the passage of time will create the political conditions for bipartisanship. The thinking goes: Obama will be long out of office, and Democrats will have come to grips with the demise of the Affordable Care Act. Moreover, Republicans would use the urgency of a deadline for protecting millions from losing insurance as a cudgel to force Democrats to cooperate. “The blame will fall on the people who didn’t want to do anything,” House Majority Leader Kevin McCarthy told reporters this week.

Maybe.

If Republicans set the deadline at the end of 2018, they would try to pressure the handful of Democrats who represent red states and face difficult reelection races to side with them. Senators Joe Manchin of West Virginia, Joe Donnelly of Indiana, and Heidi Heitkamp of North Dakota are all prime targets. Or the GOP could wait three years and bank on the likelihood that Republicans will expand their majority in the midterm elections.

But the politics could just as easily go the other way: Democrats who have struggled to defend Obamacare for years will now be on the offensive, running ads against the Republican proposal. If Republicans can’t get the votes for a new law, they will face pressure themselves to extend provisions of Obamacare that are set to expire in order to save constituents from losing insurance or subsidies that help them pay for it.

The Affordable Care Act won’t survive in its current form long past Trump’s inauguration. As my colleague Vann R. Newkirk II explained, the law gives the secretary of health and human services broad administrative powers, and Trump’s nominee, Representative Tom Price, is a leading conservative critic in the House. Even without immediate legislation, he could make regulatory decisions that undermine the law, such as declining to promote the insurance exchanges and the website through which people enroll in them. But Price can’t kill off Obamacare himself, and the law’s ultimate demise might be farther off than people think.