In 200 years, some 3.5 million Irish came to the US. In Ireland's entire existence, there weren't more than 3-4 million inhabitants in the whole country until very recently. On the whole, they spoke English (their brand, of course) and were intimately familiar with the British system of governance, at least knowing what a sheriff, an alderman, a mayor, and a judge was.
In the 45 years since the Kennedy Immigration Reform Bill of 1965 (AKA "a Black Year for America") over
35 Million Mexicans have come into the country, less than half of that number have been legal immigrants.* They and their offspring will become the dominant ethnic group of the United States, eventually (within this century) converting this nation into the northernmost outpost of Latin America.
**I know, I know. The "official number" is 12 million illegals. But that's LA County. They forgot to look in Orange County, and in 49 other states.
¡Ay-Ay-Ay-AY, canta y no llores!