Summary
Trump announced plans to end birthright citizenship via executive action, despite its constitutional basis in the 14th Amendment.
He also outlined a mass deportation policy, starting with undocumented immigrants who committed crimes and potentially expanding to mixed-status families, who could face deportation as a unit.
Trump said he wants to avoid family separations but left the decision to families.
While doubling down on immigration restrictions, Trump expressed willingness to work with Democrats to create protections for Dreamers under DACA, citing their long-standing integration into U.S. society.
They would effectively become stateless. And how they do what from there depends a lot on where they are forcefully relocated to. Assuming the majority will be forced into Mexico, Mexico has an established legal process for accepting refugees. Through the application process, if approved, you (and your family unit) would gain permanent residency. It’s not the same as citizenship, but you could stay there indefinitely and have mostly the same rights as Mexican citizens. You might run into issues with getting passports and traveling internationally, but at the least, you would be able to stay in Mexico. That depends on your refugee application being approved, and I’d imagine when the numbers cross over into the millions their established system would break down a bit and there would probably be very long delays during which you could be deported.
If it’s somewhere else, well, it varies widely. Most of the Caribbean islands have comparatively smaller populations and probably only handle migration on a small scale. It’s very hard to say how things would play out. Many would almost certainly be forced to illegally immigrate back into America.