The main use case or illicit drug detection that I as aware of was detecting fraudulent pharmacies selling shitloads of legal opiods. Which primarily affects rural white people - I don't think that's part of Nixon's drug war which primarily targeted inner city people. And the drug detection use case is only one example. IIRC anti-terror work was the first big use case for Palantir Gotham.
As far as whether or not it's an Orwellian tool, one thing to be aware of is that Palantir doesn't collect any data or have access to government data. The ingested data is still administered by the agency. I don't think they can even legally transfer it to 3rd parties.
Palantir builds tools to browse and make correlations with the data that government agencies already have. It's more of an investigation tool, not a surveillance tool. There's a substantial latency between something happening and being able to actually see it in Palantir - it needs to first be logged and recorded, and then go through the ingestion pipeline.
Sure, it's a valid position to be against government collection of things like pharmacy purchases and financial transactions. But that strikes me more of a moral position against government data collection rather than something specific to Palantir.