The discussion depends on how the issue is framed, whether it's framed as a "human rights" issue or a "law and order" issue.
Neither is correct.
Follow the money. Who benefits? Corporations who exploit "undocumented" workers by paying substandard wages for jobs "Americans won't do."
The fascists benefit.
Never mind that the border wars are raging because of the drug wars, with over 4,000 deaths now and spilling over the borders into the US. Never mind the unknown costs for social services to illegal immigrants: education, health care, welfare, crime, air tickets home (about $700), funerals, and more.
That's all corporate welfare to boost corporate profits as immigrants' native nations reduce their own costs to provide for their citizens.
Consider emigrating to Mexico legally and investigate what are the legal financial requirements and subsequent property restrictions.
Illegal immigrants got here, and they will get home when the nation's immigration laws are enforced.
The alternative is to undermine the rule of law and endorse anarchy - because it promotes corporate welfare.