Illegal immigration

  A core value of the tea party, #1, is that illegal immigration is a drain on the economy.  Some advocate a wall and putting the military on the borders.  What are the economic facts on this?  How many tens of billions would increased enforcement cost?  Many sites just talk about the cost (3-10 billion for California for example).  But what do they bring?  Almost all of their income is spent here.  Many pay into the tax system while not being able to use Federal entitlements like welfare or social security.  One site has a bunch of different takes on the problem: click here to go there.  Nationally about $113 billion is spent on them (mostly from state governments).  They produce about $800 billion of income.  Businesses benefit from this cheap labor.  They are taking some jobs from citizens but then so is outsourcing which the law embraces.  The numbers vary from the various authors.  One author argued that the loss of 5% of the labor population and the money spent by them and loss of tax revenues would be the largest disaster of our economic history.  I don't know the answer to all these numbers but there are huge costs and benefits to the illegal population living here and I'll bet that most of the critics of illegal immigration don't know both sides of the economic equation.
  There is a 2007 House report on the budgetary impact of illegals (click here to read it).  This does ignore the economic impact of illegals on the economy in spending their hundreds of billions of income here in the United States.  It only covers government costs and government tax income.