That accounts for at least 8%. Number 5 all by itself probably accounts for 10% on it's own.
The above is only half serious. I get your point, but can you see mine, however exaggerated? We don't need an exploitable under class of low skilled low paid workers, which is what McCain and others are arguing for.
It boils down to corrupt employers paying people off the books at sub minimum wages because they can't complain since they're illegal. That part of the problem, the part that talks about "jobs Americans won't do," we have to eliminate, above all else. That accounts for probably a third of the illegals. There's another third that are truly here as invaders, intent on "taking back their land." We need to root them out and imprison them for a very long time as enemy aliens, then send them back where they came from. Then there are a third who are truly hard workers who have sunk roots and become part of the fabric of our country, particularly those that have started their own businesses. Those I want to keep.
Its absurd to argue, "we can't get along without illegals"
We have 288 million citizens and 9 million working illegals.
The number of teenagers working is at all time low. They used to do a lot of the jobs illegals do.
Further, illegals are doing "jobs" that don't need to be done. In California we have illegals:
1) Working in Car Washes (Wash your own car, you lazy S.O.B)
2) Mowing the grass. (Get Junior to do it)
3) Standing on the side of the road waving "Eat at Joe's" signs.
4) Being maids and nannies to stay-at-home Moms.
That one is nonsense. the 3 to 4% who are Unemployable are unemployable because of mental or emotional handicaps, criminal behavior or other dysfunctional/handicap behavior. The idea that they can be "reeducated" is based on a failure to understand the problem. EVERY society has it "unemployable". It is result of nature, not a lack of Govt Intervention in their lives that makes it so. So there will always be a % of your population who are on the margins no matter what you do.
"Automation"
Many Economic functions cannot be automated. For example, you cannot automate Block Laying. It is a labor intensive hard dirty but well paying job. Most labor intensive employers have trouble finding good, hard working reliable AMERICANS to show up and do the work. That is why most of the crews you see have at least one Hispanic or other foreign born. The Antis can rant all they want but the post WW2 generations simply do not want to work that hard. They see manual labor as a step down, not a step up. Really funny considering some of the best paid people in our society do Construction work.
As someone who has worked Construction I assure you, MOST of your Native born who work in those jobs are marginally employables. They are completely unreliable. They have a poor work ethic, they have drug and alcohol problems, they only show up for work about 70% of the time, they have an entitlement mentality and problem with authority figures. Perfect Democrats in other words.
Also, Automation is a function of the Free Market. You cannot "Force" automation. IF there were a way to automate most functions the illegals do, they would of been automated. The most expensive machine is still more reliable and less trouble then any a gang of human employees. Plus you get the depreciation write off and don't have to pay for all the bennies, holidays, medical leave and time off.
Off shoring? How do you off shore Carpentry, Block work, Landscaping etc etc etc? So off shoring is NOW a "good thing"? Better then immigration? Economically that is a nonsense argument. You do not want to reduce your level of economic activity you want to increase it. The more increase the better. Immigration increases economic activity for a society, off shoring decreases it by moving the activity to a different society. In this case the suggest "cure" really is worse then the disease.
Stop doing stuff? Again, decreases the level of economic activity. The Free Market, not a Govt Bureaucrat, decides what economic activity is needed or not needed. This one would most assuredly be worse then the disease. Micromanaging the economy on this scale is the sort of thing Commies try. It does not work. It creates massive poverty, an equality of misery, repression and a completely dysfunctional society.
So only number 2 works out of all of your 5 points. 2. Legal (and tightly controlled) immigration