Colombian President Alvaro Uribe -- the closest U.S. ally in Latin America -- has been mired in scandal. Eight lawmakers from Uribe’s party and his former domestic intelligence chief have recently been jailed for having ties to rightwing paramilitary death squads. We speak with Gustavo Petro, the leader of Colombia’s main opposition party, the Democratic Pole. He is a Senator in Colombia and has been leading efforts to investigate ties between paramilitary death squads and top politicians. [includes rush transcript]

We turn now to the situation in Colombia – the closest U.S. ally in Latin America. President Bush arrives in Colombia on Sunday. He is making the first visit by a sitting U.S. president to Bogota since Ronald Reagan in 1982. Ahead of his trip, President Bush praised Colombian President Alvaro Uribe.

President Bush.

President Bush’s visit comes at a time that Colombia’s government is in a state of turmoil. Eight lawmakers from Alvaro's Uribe’s party and his former domestic intelligence chief have recently been jailed for having ties to rightwing paramilitary death squads. Uribe’s foreign minister also resigned last month.

Gustavo Petro is a leader of Colombia’s main opposition party, the Democratic Pole. He is is a Senator in Colombia and has been leading efforts to investigate ties between paramilitary death squads and top politicians. Gustavo Petro is also a former member of the M-19 guerrilla movement. He joins us now from Washington -- He will be translated by Charlie Roberts.

• Gustavo Petro. Leader of Colombia’s main opposition party, the Democratic Pole. Petro, is a former member of the M-19 guerrilla movement. He has led efforts in Colombia’s Congress to investigate revelations of ties between paramilitary death squads and top politicians.