Immigration is all beneficial-NOT

One more study has emerged showing the economic benefits of immigration and this time there is a letter to the President signed by 1400 economists. Once again, this is disingenuous. No sane person questions the benefits of LEGAL immigration and the letter signed by 1400 economists does not address ILLEGAL immigration. As a matter of fact, I have never seen a study on immigration benefits that is limited to ILLEGAL immigration. I assume the reason is that it is not likely to show economic benefits.