Thought I remembered the Cato Institute being very biased, then found their angle in the last few paragraphs:

Nativists have long been skeptical of these methods because, we suspect, they want to use the existence of the welfare state as an argument for reducing immigration. We propose a simpler and more popular way to resolve that complaint: Use immigration as an argument to reduce welfare. Even though immigrants use less, we can still make sure they use even less.