Undocumented immigrants are the people who clean your homes, mow your yards -- shit like that. The ones who do pay legit taxes vastly outnumber these people. The undocumented people who are working for construction companies, or large produce companies or Tyson Chicken -- legit, big businesses are absolutely paying taxes. Because the big companies want to be able to report all that payroll to the gubmint.
This is why the immigration thing is such political bullshit. Yes, get the bad seeds out and try and keep them out. I think everybody would agree with that. The ones that are here -- whether they're pursuing a citizenship track or not, if they're paying taxes (payroll, property, etc) who gives a fuck. These people are necessary to work in the companies mentioned above, the way our economy is currently set up. They need to work restaurant jobs, industrial jobs, all kinds of the 'shit' jobs Americans will not consider doing. Or we are all going to start seeing a massive uptick in the cost of ALL the things we consume on a daily basis.
Until the big companies (and rich fuckers) want to increase minimum wage and offer more benefits for these lower level positions, Americans will NOT work these jobs. Somebody has to, so enter the immigrant population. I guess being shit on in the USA is better than getting diarrhea-ed on in El Salvador. Or something like that.
But big corporations that rely on the cheap labor the immigrants provide are not going to let true immigration drawdowns actually be successful. They can't.