The left became disenchanted with heritage Americans and imported new and improved Americans.
Heritage Americans in their naivety bought the melting pot lie.
The British, the French and Germans who made up early America got along because we were still a frontier nation. There was plenty of room to segregate.
1900 or so: Yes many immigrants did segregate to a certain degree but for the most part they learned English and didn't expect handouts from the government and became proud hardworking Americans.
2019: Racist Americans need to learn Spanish or whatever. Why should immigrants be expected to learn a foreign language? Oh, and here's your free housing, schooling, health care, food, etc..... Oh, and remember you're not an American, you're a _________ dash American. And if anyone expects you to actually learn English and become an American citizen and act remotely American give us a call, we'll send the PC police to straighten them out. And remember, vote for me or the big bad wolf will take away your free stuff. Press 1 for English 2 for.......