But what about when you can't prove date of hire?
I have no hatred towards the individuals. The point is to punish the employer, thus eliminating the market that is causing some businesses to effectively invite large numbers of illegals to come in and work for money under the table under illegal employment conditions.
Why not enfranchize the migrant population. Let's open the borders, and adjust benifits for non-citizens.
The illegals are only able to get work since they can work for such low wages.
You could also eliminate the problem of illegals by exempting certain specified non-skilled jobs or completely untrained workers from minimum wage requirements.
The illegals can't be "enfranchized," because this would effectively disqualify them for the jobs that the market wants illegals for ---- which are jobs where they illegally pay undocumented workers below minimum wage. Above minimum wage, they are competing with legal residents for jobs, which causes problems, but most illegals do not have training or skills beyond the simplest of labor.
Give everyone who isn't a violent criminal and who wants it a path to citizenship. Get everyone on the tax rolls, and out of black markets.
I believe that's the case already --- there is a path to legal residency and citizenship available, which many immigrants take: the illegals are just getting an unfair shortcut by ignoring the processes established and required to become a legal resident.