On this point, you need to educate yourself more. It's cleared you've consumed the lies of right new media outlets. Immigrants contribute a lot more than they consume. See the National Academy of Sciences report[1], or read some articles from the Cato Institute, or even the short summary of the Libertarian Party's position[3].
The problem is that this country's laws hate and despise skilled and educated immigrants. My company tried for two years in a row, to bring a developer from our Paris office over into the US. A brilliant developer, who had been with us for a year, and proven himself. Someone who had graduated from EPFL (one of the best higher-education institutes in Europe -- the equivalent of CMU/MIT here). Someone who was being offered a $140,000/year base salary. Someone who spoke fluent English. And he was rejected (lost the H1B lottery) twice, thanks to the US skilled immigration policy.
That is the status quo today. Which is a far cry from what is morally right. I don't think even a preference system for educated/skilled immigrants is morally right. The only morally righteous immigration system is one that permits the free immigration of people that are peaceful/non-voilent and who are self-sufficient/self-reliant (i.e. they'll have no access to welfare, and must be able to support themselves).
[1] https://www.nap.edu/catalog/23550/the-economic-and-fiscal-co...