"The United States and Mexico have a close and complex relationship as neighbors and partners under the North American Free Trade Agreement (NAFTA). Although relations with Mexico are generally friendly, the enactment of border fence legislation in October 2006 has caused some tension in the bilateral relationship. Felipe Calderón of the conservative National Action Party (PAN) narrowly defeated leftist Andrés Manuel López Obrador of the Party of the Democratic Revolution (PRD) in the disputed July 2, 2006, presidential election. Shortly after taking office President Calderón launched operations against drug cartels in nine states. He has increased extraditions to the United States to 79 through October 2007, up from the record 63 extraditions in 2006. President Calderón has demonstrated an unprecedented willingness to reach out for counternarcotics assistance from the United States while also openly calling for increased U.S. efforts to reduce the U.S. demand for illicit drugs, gun trafficking, and money laundering. In October 2007, the United States and Mexico announced the Mérida Initiative to combat drug trafficking, gangs, and organized crime in Mexico and Central America. The Administration has requested $500 million in supplemental assistance for Mexico as part of a $1.4 billion, multi-year aid package. Migration and border security concerns have dominated the bilateral relationship in recent years. Comprehensive immigration reform was debated early in the 110th Congress, but the issue has been put aside following a failed cloture motion in the Senate on the Comprehensive Immigration Reform Act of 2007 (S. 1348)."
CRS Report for Congress, RL32724