The cruelty is the point.
Conservativism is, fundamentally, about the creation of underclasses of people who can be exploited and abused at the whims of those in control. Yes, inter-racial marriage will go on the table eventually, women's classification as "persons" under the law, anti-segregation laws, and so on.
The creation and subjugation of those underclasses is the point. It's not an accident, it's not an aberration, it's the central defining goal of conservativism as a movement. They've reached a point, whether through seeing a chance at authoritarian "victory" where they can exterminate their enemies, or desperation as progressive movements and equitable policies become more and more prevalent, where they have to rip the disguises off and go all-in, because there's no chance they can continue with the way society is going. That leaves them a desperate clawing at the reins, before they go.
Yeah, if they gain control, it's gonna be a quick trip to camps and mass killings of "undesirables", and you can already see that in their rhetoric. And it's not a zero chance. We know this shit can happen, because it has happened, and the USA has always carried this in the darkest corners of their heart, all the way back to the Founding Fathers. This isn't some new breakout, this is the slave state. This is the Confederacy. This is Jim Crow. This is internment camps for Japanese citizens. This is the Southern Strategy. It's always been there.
They just know if they can't grab control now, they no longer have a chance at a real future. So they're desperate. The USA's on the cusp of moving past this kind of brutalizing bigotry as a central defining pillar, and they can't have that.