Mamdani: The powerful have always known their answer. America, in their view, is an arena of supremacy, where only a select few are allowed freedom, where not all are created equal. America, if you ask them, becomes less the more people it welcomes. America, they will tell you, belongs only to those with the right accent or the right shade of skin. The rest of us, they insist, should be grateful for merely being allowed to visit. How small they are, how weak, how unoriginal.  At every moment in our past, those who led through exclusion and isolation have tried to win power and enrich themselves by turning us against one another. Division is the oldest trick in politics, and the cheapest. But time and again-including 250 years ago-those forces of division have been vanquished by the forces of progress. And yet today, too many of our leaders do not believe in a vision of this nation as an asylum for the persecuted-but rather as one that persecutes those seeking asylum. As we mark 250 years, what do we see?  We see a city of contradictions within a nation of contradictions. We see the wealthiest country in the history of the world— one where children go to sleep hungry while the world's first trillionaire hungers for more. We see monopolies that dominate every industry and oligarchs who buy elections. We see masked agents terrorizing our streets, eating food cooked by our undocumented neighbors before spiriting them away in unmarked vans. We see a nation whose immense wealth has been built by those with calloused, dirt-streaked hands —those who toil on factory floors and chisel into stone —and we see a nation that has allowed so much of that wealth to be held instead in the soft hands of a precious few.