How does one pay an average of 11.4 billion dollars in state and local taxes if they cannot get social security numbers?  Some steal hard working people's SSN's.  That can wreak havoc on a persons credit.  Some instances are ignored by employers.  Employers are not allowed to do that.  They also are breaking the law.  For those jobs where citizens have decided they don't want, it's because the employers won't pay minimum wage.  Again illegal, "for whatever reason".   These aren't "undocumented immigrants".  They are Illegal Aliens.