As the United States moves toward a majority-minority country, candidates for public office must increasingly make appeals to voters from a range of racial and ethnic backgrounds. In 2008, Barack Obama did this to maximum effect with white voters across the U.S. Most recently, in 2018, Beto O’Rourke nearly became the first Democratic senator from Texas since the 1990s. O’Rourke, who grew up in El Paso, speaks Spanish and is extremely knowledgeable about border issues and immigration policy more generally, which translated into strong support and turnout among Latino voters. In Campaigning in a Racially Diversifying America: When and How Cross-Racial Electoral Mobilization Works, Loren Collingwood examines the specific case of how and when white/Anglo candidates mobilize Latino voters, and why some candidates are successful whereas others are not. Drawing on extensive data collection, statistical analysis, and archival evidence, Collingwood traces the development of cross-racial mobilization across the U.S. South and the Southwest since the 1940s. Extensive cross-racial mobilization is most likely to occur when elections are competitive, institutional barriers to the vote are low, candidates have previously developed a welcoming racial reputation with target voters, whites’ attitudes are racially liberal, and the Latino electorate is large and growing. Collingwood convincingly argues—and empirically demonstrates—that to maximize the vote across the racial aisle, white/Anglo candidates must develop minority-group cultural competence and group-specific policy expertise. With these qualities, and maximum efforts at cross-racial mobilization, non-co-ethnic candidates can begin to approach the electoral benefits previously thought only accrued to co-ethnic candidates.