The goal is to force self-deportation. Whether this will be successful is too early to say.
https://www.theguardian.com/us-news/2025/jun/27/immigrants-s...
https://www.theatlantic.com/politics/archive/2025/06/self-de...
Edit for reply: As for the comparison with prohibition, I don't quite agree. The clampdown on CP, despite being just images and data as much as regular P, has thankfully been very successful. The government actually can clamp down on things, even purely digital information, when it has the will.