Book excerpt: Among the many challenges that global liberalization has posed for trade unions, the growth of precarious immigrant workforces lacking any collective representation stands out as both a major threat to solidarity and an organizing opportunity. Believing that collective action is critical in the struggle to lift the low wages and working conditions of immigrant workers, the contributors to Mobilizing against Inequality set out to study union strategies toward immigrant workers in four countries: Germany, France, the United Kingdom, and United States. Their research revealed both formidable challenges and inspiring examples of immigrant mobilization that often took shape as innovative social countermovements. Using case studies from a carwash organizing campaign in the United States, a sans papiers movement in France, Justice for Cleaners in the United Kingdom, and integration approaches by the Metalworkers Union in Germany, among others, the authors look at the strategies of unions toward immigrants from a comparative perspective. Although organizers face a different set of obstacles in each country, this book points to common strategies that offer promise for a more dynamic model of unionism is the global North. Visit the website for the book, which features literature reviews, full case studies, updates, and links to related publications at www.mobilizing-against-inequality.info.