Had congress in the 70's not opened back up our immigration (20% of all legal immigrants in the entire world come to America), and had we not had the influx of illegal aliens.... the population of the US would be ~250 million today vs 335 million.

= less water usage
= less pollution
= less CO2 (how can leftist be concerned with climate change and want uncontrolled immigration to high carbon footprint countries?)
= more $ to help the poor
= better education (who has the best education system in the world? Dump 6 million kids that don't speak their language into their education system and see what happens)