Blood of the EarthConflicts over subterranean resources, particularly tin, oil, and natural gas, have driven Bolivian politics for nearly a century. Resource nationalismthe conviction that resource wealth should be used for the benefit of the nationhas often united otherwise disparate groups, including mineworkers, urban workers, students, war veterans, and middle class professionals, and propelled an indigenous union leader, Evo Morales, into the presidency in 2006.