Our nation absolutely could deport all the illegals IF we so desired. Think of all the jobs that would be created by doing such.
That said, due to the sick mindset of the nation, that will gladly spend billions on bringing more illegals into the country, deporting them on a large scale prolly isn’t going to happen.
However, the ease and simplicity in which we could set up a system that would make illegals eagerly desire to head back home, and employers scared to death to hire illegals, is just sitting there waiting for some genuine leader to get behind it and give it the green light.
Well that's the biggest part of the problem...as a nation, we do NOT desire it. It's like over 60 per cent against. That's the "nation" you refer to.
But it couldn't be done anyway. Consider the Nazi regime and the "final solution" - NOT MORALLY, just LOGISTICALLY - look at how massive an undertaking it was to deport just 6 million people - who were in a smaller geographic area, had no advocates inside the government, and among whom there was no difference between legal and illegal status.
The effort helped destroyed their economy and war effort to even try it, and their task was infinitely easier...infinitely easier than what you are advocating.