Dallas Mayor Eric Johnson taunted Zohran Mamdani over his war on Wall Street — claiming that the Big Apple mayor’s antagonism is accelerating a stampede of businesses down to the booming Texas city. In an exclusive interview with The Post, the Republican mayor of Dallas — the fast-growing metropolis that financiers have branded “Y’all Street” — revealed that the migration of corporate titans out of New York is “only getting stronger” after the first six months of the Mamdani administration. “