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.

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

What can you tell us about the upcoming vote and the field of candidates?

Is the race about issues or is it more about a referendum on Chávez?

Looking ahead to the general election, which potential candidate would provide the strongest challenge to President Chávez?

You've mentioned a number of advantages for President Chávez. How level a playing field can we expect during the general election?

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

Placed in historical context, how significant is this election?

Is there a better or worse outcome from the US perspective? Is there potential for a significant impact on US-Venezuela relations?