Two hundred and thirty two years ago, our nation was formed through the Declaration of Independence. A critical, globally known line stands out "that all men are created equal." This concept was enough for them to defend and die for, and is at the very core of our national beliefs.
It also would necessitate either universal access to due process or none at all, for we are all equal. For this reason, removing the rights of some would greatly and unquestionably threaten the rights of all.
Immigrants may not hold the full rights of a citizen in the eyes of our current law, but they do hold a critical place in our society. Our nation is rooted in immigration, making it easy for laws to be diffused throughout the entire population. Even in our modern society, over 80% of new US citizens in the next forty years are projected to be immigrants or directly descended from immigrants.
Removing rights starts small, but history shows that it rarely stays that way. If we're willing to deny rights to a certain group of people, what's to stop us from later denying those same rights to others? If someone decides that the lack of due process has changed things for the better with immigrants, it's not a stretch to think they'd come to a conclusion that it would do the same for everybody.
It's made more complicated by the group in question. If we deny such basic rights to those who have illegally immigrated, what do we do with their children born in the United States? Technically, they're US citizens, but they have clear illegal roots. Rights to due process could be removed from them as well, effectively taking that right away from certain US citizens.
If that can be done to those citizens, why not all of them? More importantly, if it's passed on to their descendants, what will stop such conditions from eventually being applied to everyone? If it's not, what stops the parents from having children who are US citizens to grant them the right to due process, if not directly?
Those legal immigrants without documentation set an even more dangerous precedent. These are people who legally belong in the United States, but if they cannot provide proof and identification, they're denied access to a fair judicial system.
Without documentation, a person is an unknown. They could be an illegal immigrant, or they could be a legal one. They could even be US citizens, but without documentation, identification is based on their word and your instincts alone. If you were born in Philadelphia, but someone decides you're an illegal immigrant, well, too bad. You just lost your right to due process.
The fact is that our government was created to protect our rights, not remove them. It should defend equality, not create inequality. Due process is a critical right, and there's no way to be sure what would happen if it's selectively removed. If you can't be sure who's legal and who's not, you cannot be sure that you're not taking away the rights of a full citizen. It would easily take away the rights of the deserving and undeserving alike, and therefore cannot be done.