By Aaron Blake

January 5, 2017 at 7:30 AM

President Obama made a very good political point about Obamacare on Wednesday. So did his successor.

Obama told Democrats at a closed-door meeting that they shouldn’t “rescue” Republicans by helping them replace Obamacare after they’ve dismantled it. Trump meanwhile, tweeted a few pointers himself:

It’s difficult to know exactly what Trump is arguing here, or whom his advice is directed at, but the operative phrase is in there twice: “Be careful.”

That’s because repealing Obamacare is a difficult and fraught exercise, for a whole host of policy and political reasons. Such is the case when you’re trying to get rid of a massive piece of bureaucracy — and especially one with benefits people have already become accustomed to.

Which is why Obama is telling Democrats to force Republicans to replace the law themselves. Sen. Chris Murphy (D-Conn.) said it more bluntly: “If they want to break this, they own it.” They know repealing and replacing the law is a very difficult proposition for Republicans — hence the GOP’s decision to delay full repeal for as many as three or even four years — and that the promise of Democratic cooperation would only embolden the GOP’s repeal efforts. (Right now, the GOP is taking a piecemeal approach.)

They also know, as Paul Kane notes, that Republicans will own the result if things go sideways — just as they did for the past seven years. Better to let the GOP take their own crack and pay the price, the logic goes.

But why is this all so difficult for the GOP?

First, there are the mechanics of actually passing a repeal and a replacement. Our own Mike DeBonis and Kelsey Snell tackled this a couple days ago. Here’s the crux:

Democratic opposition and complex Senate rules mean that core pieces of the 2010 health-care overhaul are likely to remain, including the legal framework for the individual mandate and pieces of the state exchanges the law created. …

The rush to immediately chip away at Obama’s regulatory and domestic policies through the complex process known as budget reconciliation could create months of messy GOP infighting. The plan to vote now on repeal and work out the details later means Republican leaders will be slogging through the difficult process of writing a health-care replacement while simultaneously trying to scale back regulations in areas such as clean air and immigration, and possibly tackling a tax-code overhaul. It will be the first real test of how effective the GOP-controlled Congress will be.

Second is the challenge of getting the policy right and avoiding the pitfalls that come with deconstructing and then reconstructing such a big law over time. Gary Claxton, an analyst at the nonprofit Kaiser Family Foundation, compares Obamacare to a stool, in which the unpopular parts of the law are helping prop up the more popular parts.

For example, if Republicans want to get rid of the individual mandate (and they do) while keeping the popular requirement that insurers cover pre-existing conditions, Claxton said, “it would blow up the insurance market” because insurers would be required to accept unhealthy people without also mandating healthy people sign up, as Obamacare does.

“The longer the period between repeal and replace is, the more the market unravels,” Claxton said. “And you’ve blown up the bridge behind you, and you’re heading into battle, you can’t go backwards. You’ve gotta figure it out, or else things get really bad.”

The third obstacle is the politics: specifically, the idea of taking benefits away from millions of Americans, whether deliberately or because the GOP fails to install an adequate replacement. Obamacare would have been mucheasier to repeal had it never been implemented in the first place. But today, 20 million Americans have signed up and many other Americans have come to enjoy parts of Obamacare such as the requirement for insurers to cover pre-existing conditions and the option of keeping children on their parents’ health-care plan until they turn 26.

Republicans and Trump have said they’d like to keep these latter two legs of the stool, but it’s not clear how they’ll implement such requirements in ways that are solvent. And even if they can keep those things, you still have the prospect of millions of Americans losing a health-care option they’ve had for years. There may be plenty of Obamacare recipients who aren’t enamored of their fast-rising premiums, sure, but for many it’s a health-care option that didn’t exist before and could be taken away with an indeterminate replacement.

And indeed, polling suggests even repeal advocates are worried about losing these things. In its November poll, the Kaiser Family Foundation found support for full repeal had declined to 26 percent overall — the lowest in two years. What’s more, once you noted to repeal opponents that this could end coverage for pre-existing conditions, 38 percent of them changed their minds. And when it was explained that 20 million people could lose their coverage, 19 percent changed their minds.

Republicans insist they will replace these things, but it’s completely unclear how or with what. And the law of unintended consequences certainly applies here. Democrats are banking on it, in fact.

This is the reason we so rarely see any entitlement reforms. Americans have come to rely on Medicare and Social Security and the specific benefits they have been afforded, and any political discussion about rolling back those benefits — even for future beneficiaries — is usually a nonstarter. Look back at George W. Bush and the GOP’s aborted effort to privatize Social Security last decade, which Democrats used as a cudgel for years afterward. Likewise, Republicans attacked Democrats for Obamacare cutting $500 billion from future Medicare spending.

Obamacare isn’t technically an entitlement program, even as it has some features of entitlements in it; it’s something people have to pay for under the individual mandate — not something the government gives them for free. But there are subsidies involved, and those subsidies would suddenly be off the table, pending a GOP replacement.

Obamacare was for years the GOP’s go-to issue, and repeal was long their stated goal and promise to their voters. It was a great electoral strategy.

But nobody knows better than Obama what a hornet’s nest the GOP is walking into. Now they’re put in the position of actually delivering on that promise, and he wants them to bear the burden of the result just as he did.

It’s a hell of a way to start an administration — one that could cost you votes rather quickly. And nobody knows that better than Obama.

Amber Phillips contributed to this post.