The numbers tell the tale. In 100 years, between 1850 and 1950, some 4 million Irish came here. Some 6 Million Italians. Some 3 Million Poles. Perhaps 4 million Jews. Maybe 10 Million of everyone else, among whom were a lot of British.
Suppose some 50 Million in total came during that 100-year period. The Latinos have topped that number in just 40 years. They now outnumber African-Americans, and certainly every other distinct ethnic group.
Folks, this ain't a "Melting Pot," it's one big bowl of chili, in which ethnic groups other than hispanic hopefully can still just add a bit of flavor.