Donald Trump has just unveiled a new set of proposals designed to help working parents meet their child care needs. Yes, you’ve read that right. Under the svengali-like influence of his daughter Ivanka—“Daddy, daddy, we have to do this,” Trump claims she told him—the Republican presidential candidate has decided to take a brief respite from saying whatever outrageous things pop into his head to instead outline what he intends to do for stressed-out mothers and fathers. The centerpiece of Trump’s child care plan is a federal guarantee of at least six weeks of paid maternity leave, which he’d finance by finding savings in the unemployment insurance program.

But that’s not all! Trump has included something in his plan for almost everyone: new deductions to help defray child care costs and the costs involved in looking after elderly relatives, spending rebates for low-income families eligible for the earned-income tax credit, and much more. Given that Donald Trump is making these promises, it would be advisable to take a wait-and-see approach, as he’ll likely announce tomorrow that the media has twisted his words around and what he actually said is that he’s going to build a big, beautiful wall. What I can say with more certainty is that, whether he’s sincere or not, Trump’s championing of these proposals is a significant moment in the history of the modern Republican Party.

Over the course of his presidential campaign, Trump has repudiated many aspects of Republican economic orthodoxy. Unlike Ronald Reagan, George W. Bush, and the vast majority of conservative and libertarian economists, Trump opposes large-scale, less-skilled immigration and free trade. He has railed against Medicare and Social Security reforms designed to curb the growth of these programs, to the dismay of most conservative wonks, including many of those who are sympathetic to his restrictionist views on immigration. But Trump hasn’t ever come out in favor of expanding the social safety net. If you’re a small-government conservative who reluctantly backs Trump, the fact he has generally shied away from promising entirely new government programs is something you could just barely cling to. Until now.

On the surface—and again, the surface is all we have right now—Trump’s paid maternity leave proposal bears a close resemblance to a very good one advanced by domestic policy analyst Abby M. McCloskey in National Affairs last year. McCloskey, a conservative in good standing, has served as an adviser to the presidential campaigns of former Texas Gov. Rick Perry and Donald Trump’s mortal enemy, the famously low-energy former Florida Gov. Jeb Bush. Her proposed maternity-leave program is simple, cheap, pro-growth, and business-friendly. Right now, paid leave is a perk that enlightened employers use to retain talent. But it’s fairly rare among the businesses that employ most of America’s low-wage workers, despite the fact that it is low-wage workers who need paid leave the most. Instead of requiring all employers to pay new mothers their full salaries while they’re on maternity leave—an approach that might have the perverse effect of discouraging employers from hiring women—McCloskey proposed a modest, taxpayer-funded maternity-leave benefit that would serve as a safety net for those currently without paid leave.

Given the popularity of maternity-leave benefits, you’d think Republican candidates would jump at something like McCloskey’s proposal. Nevertheless, it landed with a thud. Neither Perry nor Bush made paid maternity-leave benefits a part of their presidential campaigns, despite the fact that it was an easy way to communicate to voters, and in particular to working- and middle-class parents, that they were looking out for their best interests, not just those of well-heeled donors. Only Trump was willing to take her idea seriously.

Were Republicans right to ignore paid leave? As McCloskey acknowledged in National Affairs, “conservatives traditionally have opposed passing laws providing or mandating maternity benefits under the belief that, in a free market, the private sector and its employees would work out a mutually beneficial leave arrangement.” And as Robert Costa and Sean Sullivan delicately put it in a Washington Post write-up of Trump’s child-care agenda, “conservative Republicans, in particular, have long seen a mandated expansion of the social safety net as anathema to their attempts to shrink government spending and give companies more control over their leave policies.”

So it should come as no surprise that conservatives have been quick to denounce Trump for embracing what looks like a big-government spending plan. During a recent appearance on Fox News, Charles Krauthammer offered a withering critique:

What [Trump] is proposing is to out-Democrats the Democrats. This is an enormous new entitlement. It will blow the debt, and when he says the mandate, he’s going to mandate from Washington, isn’t that the one thing that Republicans all agree upon of the government stepping in and telling private industry what to do? He says that will be paid for by taking out waste, fraud, and abuse from the unemployment insurance system. If you believe that, you will believe anything.

While these concerns are not entirely unreasonable, McCloskey’s proposal addressed them all. Regarding the fear about “telling private industry what to do,” McCloskey would reduce the impact on employers by having government pick up the tab: “It makes little sense from a conservative perspective that a woman who is laid off from her job could receive unemployment-insurance payments for 26 weeks, but a new mother would receive no such payments during her period of physically enforced unemployment.”

OK, but wouldn’t McCloskey’s proposal either “blow the debt,” to use Krauthammer’s phrase, or force taxpayers to bear this burden? First, McCloskey argued that keeping working women connected to the workforce would benefit the economy in the long run, and increased growth would dampen any fiscal impact. Moreover, the maternity-leave benefit she had in mind would be relatively cheap. Building on her comparison to unemployment insurance, McCloskey called for a benefit roughly in line with the average unemployment insurance payment, and that would be financed by streamlining the larger unemployment insurance program—she estimates her plan would cost $5 billion. To put that number in perspective, in 2012 the federal government spent $93 billion on unemployment insurance and $200 billion on disability insurance.

Is McCloskey’s paid-leave proposal perfect? Of course not. Is it a crazily left-wing idea that will destroy the republic? It’s not that either. It is a modest tweak to the safety net that could make a big difference in the lives of hundreds of thousands of American women who don’t currently have access to maternity-leave benefits. What (some) small-government conservatives fail to understand is that the gravest threat to the free enterprise system is not modest tweaks like McCloskey’s. Rather, it is the fact that for people stuck on the bottom of the economic ladder, the market economy looks like it is rigged against them.

I seriously doubt that Trump understands any of the nuances of Abby McCloskey’s paid-leave plan, or even that he knows why a dynamic market economy depends on a strong safety net. But it’s also undeniable that Trump did a better job than any other GOP candidate of grasping the anxieties of working-class Americans. Looking to the future, he has put down a marker for other Republicans: If he can get behind strengthening the safety net in a smart and sustainable way, why can’t you?

One answer is that, well, Trump is an insincere lunatic who is probably going to lose very badly, and there’s no reason to embrace warmed-over socialism just because he happened to favor it. Charles Krauthammer is not alone in heaping abuse on Trump’s child care agenda, and no doubt more libertarian-minded Republicans will do the same if he actually sticks with it.

The difference between the pre-Trump GOP and today’s Republican Party, however, is that small-government conservatives have lost their intellectual monopoly. From now on, they will have to do battle with populists who, like Trump, believe there is a place for government in bettering the lives of working people. If you believe the future of the Republican Party is as the party of working- and middle-class voters, you can expect more government-expanding ideas like this one. Trump’s child care speech may well be remembered as the first shot in an ideological civil war that will define GOP politics for years to come.

Read more Slate coverage of the 2016 campaign.