Sometime in April 2014, somewhere in a hospital in California, a Latino child tipped the demographic scales as Latinos displaced non-Hispanic whites as the largest racial/ethnic group in the state. So, one-hundred-sixty-six years after the Treaty of Guadalupe Hidalgo brought the Mexican province of Alta California into the United States, Latinos once again became the largest population in the state. Surprised? Texas will make the same transition sometime before 2020. When that happens, America's two most populous states, carrying the largest number of Electoral College votes, will be Latino. New Mexico is already there. New York, Florida, Arizona, and Nevada are shifting rapidly. Latino populations since 2000 have doubled in Alabama, Arkansas, Georgia, and South Dakota. The US is undergoing a substantial and irreversible shift in its identity. So, too, are the Latinos who make up these populations. Matt Barreto and Gary M. Segura are the country's preeminent experts in the shape, disposition, and mood of Latino America. They show the extent to which Latinos have already transformed the US politically and socially, and how Latino Americans are the most buoyant and dynamic ethnic and racial group, often in quite counterintuitive ways. Latinos' optimism, strength of family, belief in the constructive role of government, and resilience have the imminent potential to reshape the political and partisan landscape for a generation and drive the outcome of elections as soon as 2016.