Are you sure about that? You are saying that differentially private census data couldn't be used for gerrymeandering and advertisement while non differentially private data could? Hard to believe, I'm not an advertisement or gerrymeandering expert but I would assume people running ads or cutting up districts are mostly interested in aggregate statistics i.e. they won't care about single households? And I would assume they can rely on voter files, party databases etc... And to the contrary there are reports [1] that indicate differential privacy actually makes gerrymeandering analysis more difficult or impossible. So, not really an argument for differential privacy, discriminatory action can be equally well taken based on differentially private data as the government cares about groups not individuals and groups aren't protected by differential privacy. It seems people really fundamentally misunderstand what this technique can achieve and what it won't do.

1: https://pmc.ncbi.nlm.nih.gov/articles/PMC8494446/?utm_source...