The American dream tax is a satirical phrase written by comedian Hasan Minhaj. The joke compares the perspectives of an immigrant versus those of their first-generation children born in the United States.
Immigrants feel obligated to justify the hardship endured such as bigotry and micro aggression as the cost of entry to something greater.
Here is Hasan Minhaj explaining the concept.
YouTube: Comedian Hasan Minhaj on political satire and ‘the American Dream Tax’