Under the table cash payments to illegal immigrants create an opportunity for funding and funneling cash to the drug cartels and terrorist organizations, both of which are enemies to life, liberty, and the pursuit of happiness.
The off-the-grid, transient lives of many illegal aliens fit well with the infrastructure of drug cartels and terrorist organizations that thrive on clandestine cash markets. The Taliban in Afghanistan funded al Qaeda through the heroin trade. The federal government spends a fortune fighting drug wars, yet it foolishly refuses to enforce the immigration laws and thereby encourages the growth of an entire population that is essentially untraceable and unaccountable.
Black markets, off-the-grid economies, identity fraud, and consumption of public facilities and services, all form the tapestry of illegal immigration, each element eroding the economic strength of legal citizens by unfair competition for work and by shifting the costs of public services onto the legal residents and citizens.