In the preliminary round of an election former U.S. Ambassador William Luers calls "the most significant of our modern era," Venezuela will hold a primary to select a candidate to oppose President Hugo Chávez in October's general election. Opposition candidates contending in the primary include current front-runner Henrique Capriles Radonski, governor of the state of Miranda (Primero Justicia; Capriles was endorsed last week by Leopoldo López, former mayor of Chacao, following his withdrawal from the race); Pablo Pérez, governor of Zulia state (Un Nuevo Tiempo); and Congresswoman María Corina Machado (former director of the civic organization Súmate). To gauge the field and look ahead to October, we spoke with pollster Luis Vicente León and former US Ambassador to Venezuela, William Luers.

William Henry Luers served as United States Ambassador to Venezuela (1978-82) and Czechoslovakia (1983-86).

Luis Vicente León is president of the polling firm, Datanálisis.