If there's one thing you can say for sure about Donald Trump it's that he's full of surprises.

Perhaps the biggest surprise he's pulled since throwing his hat into the ring for the office of president of the United States is his recent speech outlining his ambitious pro-family policies. The two biggest planks of this proposal are mandatory paid maternity leave, to be paid for by the government, and the deductibility of childcare expenses from income taxes.

This is the smartest thing Donald Trump has done so far in his campaign, both in terms of politics and policy.

Women, particularly moms, are obviously one of the most important constituencies in any election. Women swing presidential elections. On top of that, giving women concrete benefits for motherhood, even though it has historically been against some version of conservative movement orthodoxy, is actually deeply consonant with the "family values" the GOP is supposed to stand for.

It's also a nice bit of triangulation, specifically for Trump, and even more specifically in this election. Here he is, taking the offense on an issue dominated by Democrats, openly courting women, in the face of the first female major party presidential nominee ever.

In terms of policy, family formation and maintenance just might be the single most significant issue facing America. Sure, there is some merit to conservatives' libertarian-influenced opposition to mandatory maternity leave. As a matter of economic cost, it makes it more expensive to hire women. But at the end of the day, the cost is almost certainly minimal versus the benefits.

This issue affects everything. It affects people's health and well-being. Right now, it's harder than ever to start a family, and it's harder than ever to keep it together. Financial pressures aren't the only reason, of course, but anyone who has ever been in a family knows that financial pressures do matter to family health. Divorce is never fun for anyone involved, but it's especially hard on children. One could fill reams and reams of paper with studies showing how single parenthood can lead to a variety of social ills for children and society. Children brought up in a stable two-parent household get a massive boon to their well-being. This matters intrinsically, of course, but is also key to long-run economic growth since it endows them with the sort of human capital that leads to a prosperous society.

Now, of course, there is some score-settling to be done here. I'm part of a group of conservative writers known as "reform conservatives" who have argued for making pro-family policy the center of the GOP's domestic platform for many years. And for many years, we were sneered at in places like The Wall Street Journal editorial page for being sellouts, and warned that if the GOP's working-class base didn't get meaningful policies from the Republican elite, it would either run away or revolt. To which I say: Congratulations, guys. Enjoy Donald Trump.

Trump is, in many ways, the evil twin of reform conservatism. Trumpism is based on the same political phenomenon — the fact that the GOP's white working class has been ignored by its elites — but exploits it almost only through demagoguery. (The Mexicans will pay for the wall! Trade war with China!)

His entire presidential run has been about slaughtering every sacred cow of Republican orthodoxy, and his astonishing success within the party shows how bankrupt that orthodoxy was. One of the questions surrounding the aftermath of the Trump campaign is whether the party will switch back to that orthodoxy and pretend nothing happened, or become the party of Trump, or achieve some kind of new synthesis.

It remains to be seen whether this surprising move by Trump will prove politically popular for him, or whether it will be lost in all the Sturm and Drang. But for once — for once! — I'm glad Trump killed a GOP orthodoxy. I hope it stays dead.