You start deporting everyone without a green card and you'll quickly find out that there's several little fragile elements to the labor market that break and then all hell breaks loose and you're looking at empty grocery store shelves.
Listen, I don't like illegal immigration one bit and I think it's one of the nation's most pressing problems, but you're not going to fix 50 years of bipartisan bad policy that's resulted in the distortion of the labor market and the physical displacement of tens of millions of people with a stroke of a pen. Someone will need to sit down and actually think about the problem and then implement some nuanced solutions. It'd be different if we were talking about 10 million people who were just sitting around unproductively collecting welfare checks while at the same time the natural-born population was expanding at historically-normal levels, but that's not at all representative of the situation.
Yup. Someone will need to sit down and actually think about the problem...perhaps go thru the dole rolls. Severely.
Capitalism has ways to fill gaps, easier still with forethought.
Again, It's only as complex of a problem as folks want it to be. Lots of folks want it to be too complex of a problem...