To him, that meant rapists, drug dealers, and murderers, because he's a rich Manhattan/Connecticut conservative, disgusted by and suspicious of people who work with their hands. "The wall" is something that has been added to in a bipartisan way by xenophobes from both sides of the aisle for a couple of decades at this point, and it was somehow used as evidence that he's more racist than the rest of Congress in combination with that remark.
Sadly, it turned out that the image that the media smeared him with was even more attractive to a majority of white American men than the "I make good deals" persona alone, he immediately became unstoppable, and leaned into it as far as he could. Not that I'm saying that he hasn't always been a bit racist (most libertarian conservatives are), but I don't think that it was a dominant part of his worldview, or that he would have ever dreamed of running for President on a primarily racist platform.
Hope I didn't say anything offensive here, I tried to be careful...
I don't quite get this.
What do you mean by "libertarian conservative", and where do you get the idea that most are racist? Libertarians and conservatives might superficially seem to be aligned in many ways, but when you look at it, libertarians align with liberals in just as many ways... so "libertarian conservative" isn't really a meaningful term in the strict sense.
I guess you could say "conservative with some libertarian tendencies", but anyone who is actually a libertarian is pretty much not racist by definition, given that libertarianism is a pretty much a radically individualistic ideology in which skin color, ethnicity, race, religion, gender, etc. play no role at all.
Libertarianism is a radically collective ideology that wishes to shrink government into a police force to protect property, and a totalitarian bureaucracy that catalogs the ownership of every object that its police force can reach. It is an ideology that insists that skin color, ethnicity, race, religion, gender or anything that ever happened in the past play no role at all in the present.
Or rather, that's how I feel about it. And in my experience, all libertarians that I've met have harbored ideas that I think of as racist (even the very nice ones, and very insightful ones), and I've observed that when you see libertarianism grow, you see overt racism grow within its protective bubble.