No country has infinite resources able to sustain infinite population numbers. Certainly the USA doesn't. The people of the US have the right to expect its government to know who has come into our country, why they have come here, and where they are located. It doesn't know any of that about people who come here illegally. Starting with Reagan's amnesty in the 1980s (which I supported at the time), illegal immigration doubles everytime a president even whispers that word. In California alone, 70 hospitals and medical facilities have been forced to close because the enormous burden of providing "free" OB/GYN care to illegals... while being forbidden by law from even inquiring about their legal status. This is unacceptable.
And brings me to my next thought. We should amend the constitution to rescind the automatic citizenship rule. Made sense when we were nation-building in the 1800's and early 1900's (when nearly all immigrants came through Ellis Island and were processed). Does not make sense now, especially when "anchor babies" (yes, I know some people get uppity about the term, but that's exactly what it is) encourage illegals to give birth here to American citizens, which are then immediately afforded access to entitlements... otherwise known as taxpayer money. I'd rewrite the law to state that at least one biological parent must already be a citizen, by birth or naturalization.
Yes, we need to make it much easier for productive foreign nationals to enter the US legally, so they can work, pay taxes, contribute to the country. I'm all in favor of that. But first we need to control the borders and keep track of who is inside our own country.