You have a strange understanding of the word "artificial". Anything that is forced to happen because of a law is by definition artificial. If it happened naturally that way, you wouldn't need the law in the first place. When you say "illegal labor artificially lowers the cost", you words are contradicting themselves. Illegal labor naturally
lowers the cost of things in the US. But, the legality of the labor really has no bearing on the economic issue, so lets just say "Cheap labor lowers the cost of goods in the US" and move on.
You claim that this cheap labor does three things:
1)Makes it hard for workers to earn a "living wage"
2)Artificially inflates the value of earnings
3)Creates an enslaved class of people
On point (1), the idea of a "living wage" is nebulous at best, and is an idea that is kicked around in pompous academic circles as a time-wasting pontification, largely influenced by what the individual defines as an acceptable living condition for themselves. The reality is much simpler. If a worker finds the compensation acceptable, they will take the job, if they don't, they won't. This is what a natural market is.
On point (2), in what way can cheap labor possibly inflate the value of earnings? This is not tied to the value of labor in the slightest. It is completely tied to a corporate decision to not pass on the savings from labor to the end customer, and can only happen in a government created false economic infrastructure of tariffs, penalties, and regulations that favor certain corporations and industries at the expense of others. If not for this, true competition would force
such companies to pass on these savings.
On point (3), the enslaved class of people you speak of is not caused by cheap labor (or illegal immigration). It is the result, again, of government meddling in the lives of every human being within its borders. Government requirements, regulations, and taxes have created entire industries of unproductive people whose only purpose is to help other people comply with all of the mandates. Despite this, people who naturally excel will excel. People who don't, won't. Capable people always find their way out of this type of "enslavement".
Yes, Americans would complain if the cost of lettuce tripled. But what is it they would be complaining about? Illegal immigration? Hardly. They would be complaining because it is plain to see that a head of lettuce is simply not worth ~$6. They would be complaining about the government mandated policies that cause lettuce to be that expensive.
Minimum wage is an abomination in a free market economy. It kills jobs, it eliminates opportunity, it creates false expectations that lead to ideas like the concept of a "living wage". Yes, Rome is burning, but it is not because of immigration. In fact, the lack of immigration control/enforcement will help this crumbling country successfully stay alive just that much longer.