“I’m not sure “language and culture” has anything to do with even Goldwater or Buckley’s vision of American conservatism”
Certainly not Buckley. He was the father of Modern Conservative Orthodoxy. And it’s Modern Conservative Orthodoxy which destroyed the Republican Party. Free Trade, War and Open Borders. They integrated the Neoconservatives and didn’t foresee the outcome.
Goldwater was a different, unique sort of Western libertarian. A fusion of southwestern individualism and free markets, low taxes, small government.
But the paleoconservatives like Buchanan and Russell Kirk (and now, Trump) have always held borders, language and culture at the center. If you want to use the word “nativism”, just know it’s seen as a derisive term on the paleo right.
BTW: The Neocons suffered a total and complete defeat in the GOP primary in 2016. They have been rejected. Completely. They’ll have to go back to the natural home for Marxists, the Dim party.
Neocons are basically the old Scoop Jackson Democrats, who got kicked out of the Democratic Party, much like the Dixiecrats.
Buckley was the prototype for today's GOP establishment, so naturally he didn't care about language or culture. Goldwater was (as Mariner says) a libertarian, who also don't make cultural issues a priority.
Buckley and Goldwater were both fiscal conservatives who opposed the welfare state. That's commendable, but it doesn't nearly go far enough. Fiscal conservatism by itself won't keep the US from being transformed into Mexico del Norte in everything but name, or keep our cities from turning into slums and gang war zones. Only fiscal conservatism wedded to a nationalist worldview can accomplish what needs to be done.