Entrepreneur Visa Guide | USCIS
EB-1 Extraordinary Ability | USCIS
If you have a level of education and professional credentials for some skill in short demand -- getting an immigrant visa to the USA is not that difficult. If you are capitalizing a new business, with millions of dollars -- not an aspiring Uber driver, a new business that is of some national interest, you should not have a problem.
Immigrant mid-level workers with limited skills are not needed as they would only compete with US citizens' employment opportunities.
Emergency Quota Act - Wikipedia, the free encyclopedia
My grandparents got into the US before 1921 they were primarily economic immigrants -- the 'better immigrants' you allude to. Those type of immigrants en masse just are not needed, nor wanted, today. Refugee immigrants today (to the USA) are of a humanitarian motivation foreign policy decision. Those decisions are above a lot of peoples' pay grades around here ...