Senate Republicans are walking into a trap, and Donald Trump might be the only person who can save them from themselves.

Republicans want to repeal Obamacare. That much we know, and we’ve known it ever since Obamacare was first signed into law. Had Mitt Romney been elected president in 2012, undoing the Affordable Care Act would have been relatively straightforward, as the Medicaid expansion and the health insurance exchanges didn’t kick in until 2014. Repealing Obamacare now would have huge real-world effects. It would mean taking insurance coverage away from millions of people—unless, that is, Republicans can coalesce around a replacement that will cover all those people or at least get in the same ballpark.

Republicans, though, are far less unified around what a replacement ought to look like than they are in their opposition to Obamacare. There are a couple of ways of going forward.

Option No. 1: GOP legislators suck it up and do the hard work of passing piecemeal health reform legislation, with the help of centrist Senate Democrats. The smartest approach would be to give up on starting from scratch, at least for now, and instead give people who can’t or won’t buy Obamacare-compliant insurance plans the option of buying cheaper, less-comprehensive insurance without premium subsidies. Subsidized Obamacare-compliant plans would still be available on the exchanges, which would serve as a safety net for those too sick or too poor to afford bare-bones plans with high out-of-pocket costs. Instead of pulling the rug out from under states that expanded Medicaid under Obamacare, Congress could pick up a higher share of the tab for the poorest and sickest Medicaid beneficiaries while asking states to take on more responsibility for helping the healthiest of them, a swap that would greatly relieve the pressure on state budgets. In short, rather than taking a wrecking ball to Obamacare, Republican lawmakers could act as sculptors, chipping away at the provisions they like least.

Option No. 2: Repeal Obamacare without a plan for replacing it and hang a “Mission Accomplished” banner while America’s health insurance market erupts in flame.

Naturally, Senate Majority Leader Mitch McConnell appears hellbent on Option No. 2. This is “repeal and delay,” a strategy for unraveling Obamacare in the messiest, most chaotic way possible.

Because Senate Republicans have a narrow 52-seat majority, they can’t overcome a Democratic filibuster, so they can’t really repeal Obamacare root and branch. The only way to get to a filibuster-proof majority is to embrace Option No. 1. What the Republicans can do without Democratic votes is use the budget reconciliation process—which requires a simple majority vote—to roll back Obamacare’s premium subsidies, its payments to states that expanded their Medicaid rolls, and its tax penalties targeting those who choose to go without insurance coverage. Republicans in Congress passed a bill in early 2016 that did just that, which President Obama promptly vetoed. Once President Trump takes the reins, the thinking goes, Republicans can get a big win under their belts, establish their conservative bona fides, and then press ahead with slashing taxes and regulations.

Repeal and delay wouldn’t cut off the flow of Obamacare funds immediately. It would give Republicans in Congress until 2019 or 2020 to come up with a viable replacement. So what could possibly go wrong? Pretty much everything.

The Obamacare exchanges are already in shambles, because they’ve attracted an older, sicker set of enrollees than the Obama administration had anticipated, which has driven up costs. Obamacare was designed to nudge younger, healthier people into enrolling on the exchanges by threatening them with steep penalties if they failed to do so, but the penalties have either been delayed or haven’t had much bite. President Obama wanted to give insurers open-ended subsidies to compensate them for these higher-than-expected costs, but Republican lawmakers intervened, insisting this would amount to a bailout for the insurance industry.

The end result has been a highly unstable insurance market, from which major insurers are constantly threatening to jump ship. Instead of easing these pressures, repeal and delay would further destabilize the market. Eliminating the tax penalties would give the young and healthy even less reason to buy insurance. Once the subsidies are placed in jeopardy, even more insurers will lose interest in offering plans. Low- and middle-income enrollees who currently receive premium subsidies won’t be able to afford their insurance. Repeal and delay, then, is a recipe for tens of thousands of individual health care horror stories, heart-wrenching tales Republicans would have to answer for.

There’s also the nightmare that would befall state governments, including Republican-led state governments, that embraced the Obamacare Medicaid expansion. By zeroing out the federal payments that made the Medicaid expansion possible, repeal and delay would bring on crippling budget crises. Just imagine the tongue-lashings Republican governors would give their home-state senators or the rowdy town halls where Republicans members of Congress would find themselves burned in effigy. It’s not a pretty picture. Honestly, the only way repeal and delay makes sense is if you’re a small-government true believer who’d rather see the GOP destroy itself than sell out.

But wait: Wouldn’t Republicans have years to craft a functioning Obamacare replacement? Well, sure. But they’d still have to unify the GOP and attract a handful of Democrats. How exactly would they do that if repeal and delay set off a massive national backlash? And what if Democrats smelled blood in the water and sensed they had a decent shot at taking back the House? Repeal and delay assumes Republicans will have more leverage in two or three years than they do today. That’s not obviously true.

The good news is that a handful of Senate Republicans get that repeal and delay would be an epic disaster for the GOP, so they’re pushing back against McConnell. Maine Sen. Susan Collins has come out against it, which is not shocking considering she represents a Democratic-leaning state. More surprising is the opposition of Kentucky Sen. Rand Paul, who has said he’s opposed to repeal and delay because it adds too much to the federal budget deficit. Louisiana Sen. Bill Cassidy, who has a reputation as an obsessive health care wonk, has also expressed skepticism about repealing Obamacare without having a replacement ready to go. And as of Thursday night, Arkansas Sen. Tom Cotton, a leading light among younger conservatives, has joined the rebels.

You’d think that objections from at least four senators, who almost certainly speak for several others, would be enough to get McConnell to shelve his repeal-and-delay plans. But most senators, like most humans, are wimps. If McConnell forces GOP senators to choose sides on a repeal-and-delay bill, he knows armies of conservative activists will pillory any “nay” voters for having kept Obamacare alive. That prospect might not frighten Susan Collins, who has every incentive to present herself as a level-headed centrist. But it might be enough to bring the other dissenters in line.

Unless, that is, Trump gets in the way. Trump’s tweeting earlier this week managed to spook House Republicans out of weakening the Office of Congressional Ethics. Now, he’s taken to Twitter to suggest he wants Republicans and Democrats to work together to replace Obamacare with a better and cheaper approach to providing Americans with insurance coverage. Could this be a signal that Trump doesn’t want Congress consumed with a slow-motion Obamacare meltdown? Might he be more favorably disposed to Option No. 1 (play nice) than Option No. 2 (let slip the dogs of war)? More to the point, could Trump give cover to Senate Republicans who don’t want to go along with McConnell’s kamikaze strategy? There’s no way of knowing. Trump could tweet the exact opposite sentiment five minutes after I publish this story.

But how weird would it be if Trump—a man who seems blithely indifferent to the nitty-gritty details of policy, and who’s had no compunction about belittling his fellow Republicans when it has suited his purposes—managed to prevent Republicans in Congress from making a colossal policy blunder?