As you correctly surmised, the quote is from Andrew Sullivan's The Weekly Dish. My comment was to state that in my opinion, Goldwater was the last American Conservative to embody any of the qualities in the quote.
I have no respect for him anymore, only hot disdain for he is not an egalitarian (he pretends he is but he reveals himself again and again)
If you want a counter opinion on the nature of American's Conservatism I would argue the frontier touches everything providing a concept of Liberty as freedom from restraint. But that is not the only definition of freedom in world history let alone in US History. And when I say the frontier touches everything you are defining as conservative how each generation saw the frontier and why it is good or bad, good and pure, good vs wicked is different. Why we want the frontier is in flux.
This book 2019's The End of the Myth: From the Frontier to the Border Wall in the Mind of America by Greg Grandin does a good job of exploring the history of it.
Likewise this podcast is a good 2 hour condensed version where Greg Grandin is interviewed about it. It talks about how Franklin, Maddison, Jefferson, Washington saw the frontier and then it goes through the generations afterwards.
https://www.thedigradio.com/podcast/end-of-the-myth-with-greg-grandin/