Steve quotes a lot more of the piece and comments on it here [link], and the comments on his post are, as always, very much worth reading. So do go there and do so. A lot of what I'm about to say here mirrors what Steve and his commenters have already said, but I'll add, I hope, a little Ex-Army flavor to it.
In the first place, Douhat mischaracterizes Reagan and Reaganism pretty seriously. especially given the ambiguousness of some of his terms.
"Social conservatism" is a very broad concept, stretching all the way from advocating criminalization of thing like abortion, certain drugs, and a whole range of sexual behavior, to insisting that the government refrain from promoting all those things. Reagan may have been a bit fuzzy on the difference, but he mainly emphasized the latter rather than the former. If his position was "conservative," then Trump's position is more conservative than that of Conservatixm, Inc.
As for free-market economics is concerned, yes, Reaganism called for as much of that as possible without putting it ahead of the interests of the country as a whole. Conservatism, Inc. calls for free trade above all else, and to hell with the American people if, in a given instance, free tradeis to their detriment. Here again, Trump is clearly more of a Reagan conservative than the nomenklatura of Conservatism, Inc.
Finally, as for that "hawkish internationalism," we actually got very little of that from Reagan. Mostly he used the bully pulpit to criticize our opponents, not threaten them. He helped bring communism down by maintaining a strong defenxe and offering a philosophical alternative. He didn't call for extending NATO to the edge of the Kremlin and playing chicken with the Soviets. He was, if you'll remember, also anti-communist, not anti-Russian. Conservatism, Inc. seems to be the latter. Again, Trump scores better on the Reagan scale than do his "conservative" detractors.
I'm getting a lot of this from Steve's post and his commenters, BTW. Do go read it all if you haven't yet.
So, to summarize, and say it all over again:
Conservatism, Inc. is the establishment that calls itself "conservative." It is not conservative, it is neoconservative, which is almost the exact opposite of conservative. They are the ones screeching that Trump is not a conservative. Trump is a nationalist, who believes that the purpose of the U. S. government is to protect the interests of the American people. He thinks that the best way to do that is to be careful who we allow to immigrate, to negotiate trade deals that work to our advantage, and to conduct foreign policy based on what is good for the American people.
Conservatism, Inc. says no. They say that the U. S. government should put the interests of the whole world first (see my previous post on Jacobins [link]), and that the interests of the American people are secondary. They call for de facto open borders and mass immigration to benefit fat cats like Zuckerberg who want cheap labor, and try to justify it all by saying that depressing wages and putting Americans out of work will somehow benefit us all in the long run. They also are perfectly happy with trade deals that screw over the American people, because their donors benefit from trade deals like that. And, for a number of reasons, Conservatism, Inc wants a belligerent foreign policy of sticking our nose into everybody's business and overthrowing stable governments in the Middle East, especially. And, for some strange reason, they also want to be belligerent as hell to Russia, much more belligerent than we were when it was a communist country.
My conclusion? This is the first time that the Republican party has nominated an actual conservative for President since Reagan. Both Bushes, Dole, McCain, and Romney were all neocons, and Conservatism, Inc. liked it that way and are terrified that Trump might turn us around and give us an actual conservative government.
The thing you all have to realize is that the people telling you that Trump is not a conservative, are not conservatives. They are big-government interventionists who have no plans to do anything about "social conservatism" except talk about it. They all want, for a variety of reasons, to bring in tens of millions of Third World immigrants. On almost every issue, their position is, at best, only slightly to the right of liberals.
Actual conservatives, if they consider the facts, should be glad that they have their first opportunity in 32 years to vote for a conservative Republican.