Ending birthright citizenship.
Stephen Miller, Trump, Heritage Foundation, and others want to end birthright citizenship.
You may think they can't do so as they would need to repeal the 14th amendment. But that isn't their plan. Their plan is to reinterpret the 14th amendment to exclude children of immigrants.
The courts have repeatedly rejected this interpretation of the 14th amendment, but that's little solace when dealing with individuals like Miller and Trump who talk of openly ignoring the law.