About the only major screwup here for effective mass deportations is the Trump administration is hiring too few people to round up these people. Back in the 1940s when we were rounding up Japanese to send to concentration camps, it took way more manpower to effectively round up that population to send them to squalid, disease filled camps we sent them to, and there weren't 6 million to be rounded up either.
Hopefully this will get more Americans politically active at the very least, as when the food is rotting in the fields due to a lack of farm hands, that is when we will see something similar to what is happening with Obamacare and Republican voters right now.