Immigration is not a function of only US job “demand.” In fact, for decades, no matter what US economic conditions were at any given time, legal immigrants have been coming at the rate of 1 million a year. And since the last Amnesty, illegals have flooded in at a rate of over 1 million/year during all US economical cycles.
Why? Because immigrants & illegals don't consult the Wall Street Journal, Barron's or the Bureau of Labor Statistics before leaving.
They come hell-what-may because they know the worst conditions in the US are better than the best conditions for the vast majority in the 3rd world. Because their standard is merely “better than 3rd world” - they can always 1) work for less than Americans 2) live well on extensive public assistance and private charity unavailable back home 3) take advantage of criminal opportunities unavailable or more mildly punished than in their home country. (You can't follow the news, without noticing how prominently foreigners figure in stories of medicaid fraud, food stamp fraud, earned income credit fraud, drug rings, prostitution rings, and on and on.....)
They know that even working only a few days a week, the peanuts they earn will still be more than what they can earn by breaking their backs 7 days a week in their home country. Even working part-time or not at all, they can live better here. Do you think “poor people” in Mexico/China are obese, have wide-screen TVs, get food-stamps, have their kids fed free breakfast and lunch in school, can walk into any hospital and get the most modern medical care for free...?
If America does not control them - by controlling the borders, making life much more difficult for illegals living here and enforcing laws that deport legal immigrant who accept public assistance - they will keep flooding in, irrespective of US economic cycles - until the US sinks to near 3rd world living standards.
Couple things.
1, 1 million a year is not going to bring about this result.
2, If they are so poor as you claim - they will not have the means to come to America, nor will they leave.
3, This ‘hellhole’ of China and Mexico, China has a space program.
4, The vast majority of American immigration (both legal and illegal), comes from hellholes like Mexico, Canada and the Phillippines. All fellow Christian countries with significant legal and historical ties to the United States.
5, The problem with illegal immigration is not that immigration is in itself negative - but that the immigrants have chosen to break the law in coming to America. The problem is when they stay and they continue to break American laws without impunity. Sovereignty is only asserted through defense of one’s borders, and through control of immigration. Without control, there is no sovereignty.
6, Does it matter where they come insofar as they contribute? This is why legal immigration is so important - if they are here to contribute then they can follow the correct process.