Parent mentioned that AI is used to sneak in discrimination through the back door, implying that discrimination wouldn’t be there (or there would be less) without AI.

Here's an example: mortgages (in the USA) used to be approved or denied by humans, but there were certain neighborhoods where only white people were allowed.

Now, there's a law against that.

In the future, there will be an AI system to approve or deny mortgages, based off of historical training data. Since that data includes the redlining era, the AI will learn to make racist decisions.

Most people do not understand how it is possible for a computer to be racist. (Other than against all humans like in Terminator 2.) This is why it's "through the back door", because it's not obvious how it's possible or where it's coming from.

"Since that data includes the redlining era, the AI will learn to make racist decisions."

This is a crude assumption.

AI researchers are well aware of these potentialities, and you'd (or the government) would have to provide evidence that these systems are racist before banning them.

The basic premise you're making is: "The world is unfair -> AI uses data from the real world -> the AI is racist".

Insurance fiduciaries already use an incredible amount of 'training data' in their work, and we don't have hugely material problems there.

The OP mentioned "AI that makes opaque life-changing decisions". In that context, "through the back door" was more likely meant in the sense of "without anyone noticing".

It doesn't really matter if there is "less" discrimination without AI. While AI is not there, there is no discrimination from AI. If there is some after introducing AI, then it's a problem with AI.