Sometimes winning an election can put you in a really difficult spot. That's what's happening now to congressional Republicans who suddenly control both the House and the Senate and are expected to make good on their repeated campaign promises to repeal the Affordable Care Act, President Obama's signature legislation, the very minute they take office.

They've already started that process, with Republican Senator Mike Enzi introducing a budget resolution intended to cut Obamacare off at the knees by discontinuing penalties for uninsured individuals and employers who don't provide insurance to employees among other things. Using a budget resolution makes passage of the repeal easier because it can pass with a simple majority in both houses.

But for Republicans to take down Obamacare without unleashing a flood of public protest, they will have to solve a few tough problems:

1. What will they replace it with?

Almost from the moment Obamacare became law, it came in for harsh criticism. Republicans at the time simply wanted to repeal the law and put things back the way they were. But now that it's been in place for three years and more than 20 million people have insurance who didn't before, it may be tough to simply roll back the clock. Nor would that fit with President-Elect Donald Trump's repeated promises to "replace it with something much better." Trump's choice of Tom Price as head of Health and Human Services signals that he's serious about not just repealing the law but also replacing it with something. Figuring out how that something will work could take quite a while.

2. What happens in the meantime?

Understanding that replacing Obamacare with some other insurance framework will not be quick or easy, many Republicans have proposed a "repeal and delay" approach. Sort of like Brexit, the U.K. exit from the European Union, the idea would be to make a plan but then take a couple of years--or maybe longer--to carry it out.

But while the British government can take years to figure out its EU exit strategy, repeal and delay is likely to cause a lot of public unhappiness. That's because insurance companies (whose support for Obamacare was always crucial) won't like the uncertainty involved. There's a good chance that most of them will react by simply pulling their plans out of the state-wide insurance exchanges, rendering the exchanges useless.

That might seem like a good thing since the exchanges have proved unpopular and technologically deficient. But there's a problem: Under Obamacare, subsidies for health insurance plans only apply to plans purchased through the exchanges. Eighty percent of Americans who get their health insurance through exchanges benefit from these subsidies. Without insurance companies offering plans through the exchanges, millions of Americans who could only afford insurance with those subsidies won't be able to afford it anymore.

3. What happens to people with pre-existing conditions?

Before Obamacare, 11 states had laws requiring insurers to cover everyone, regardless of pre-existing conditions or their state of health. If Obamacare is repealed without replacement, people in the other 39 states may face difficulty buying insurance at all at any price. Pre-existing conditions can be defined as anything from obesity to diabetes, to taking certain medications. According to an analysis by the Kaiser Family Foundation one out of every four Americans would be unable to buy individual insurance due to some pre-existing condition or other. (Those whose employers provide insurance might still be able to get it that way.)

For insurance companies, the requirement to cover the sick has always been balanced by the requirement that healthy people must also buy insurance or face a financial penalty--known as the "individual mandate." But the individual mandate is one of the most unpopular elements of Obamacare and one the Republicans are in a hurry to get rid of. Without the individual mandate, insurers will likely either stop insuring individuals with pre-existing conditions or raise premiums and/or deductibles to stratospheric levels.

4. What about wellcare?

A key philosophy behind the Affordable Care Act is that we are better off as a nation keeping people as well as possible rather than performing the maximum number of medical procedures. Obamacare compensated some hospitals and medical conglomerates based on the wellness of their patients rather than the procedures they did. It also required insurance to cover preventive treatments designed to avoid illness or catch it early, including things like mammograms and colonoscopies. Millions of people, wherever they get their insurance, have benefited from this requirement that they receive preventive treatment for free. Without Obamacare, they may suddenly find they have to pay for these procedures again.

How will congressional Republicans answer all these questions? There's no way to know. Given their campaign promises, they can't sit on their hands, and repeal and delay is unlikely to work well. What other options are left? We'll soon find out.