(us history/politics) question: is contemporary conservatism more influenced by opposition to the 16th amendment or opposition to the 1964 Civil Rights act?

This is what I've been thinking about lately as I descend into a Barry Goldwater retrospective hole.

Because Goldwater wasn't a segregationist, but his opposition to the Civil Rights act was still seen as a major "turn" in Republican orthodoxy.

Like, to quote here: One of the oldest, though hardly the most efficacious, of the traditions of many conservatives in the North— and even to a degree in the South as well— has been a certain persistent sympathy with the Negro. c. 1965

And while Alexander Hamilton was hardly the abolitionist / civil rights freedom fighter he is today according to popular legend, it is true that his philosophy was preoccupied with the tyranny of the majority.

So, like, that's a weird but central form of conservative philosophy that aligned the poorest and the richest as minority interests that needed to be protected from a skeptically viewed multitude.

There were a lot of people like this still in the mid-1960s.

And Republicans today who deny the "Southern strategy" as liberal whatever are right when they say that the Civil Rights act was bipartisan.

But anyway like… the thing is now conservatives are embracing the populist rhetoric of the deserving middle class while also still

maintaining that classic, old school anti-tax line

I mean I think as a historian that single-factor explanations are basically to be avoided but also as a historian it's hard to resist their appeal.

A more currently-worded question: is this adherence to old school trickle-down theories gonna screw over Trump w/his supporters eventually?

Or is policy just not a vulnerability of his?