> If the stated purpose makes sense ("stop illegal immigration"), they will dismiss tragedies as routine accidents of an imperfect world.

Indeed, this is the modus operandi, though I'd argue that it doesn't have to make sense but rather be in the political canon. I recall hearing arguments that "some gun deaths are necessary" (in the context of mass shootings at schools) for us to have our "god-given right" to own guns, but the purpose—owning guns for the ability to... checks notes... stand up to entities that can legally commit violence against you—isn't so obviously sensible.