The agenda for the meeting is predictable; issues to be discussed include trade, security, counternarcotics programs and the polarizing immigration and border control debate.

Bush's trip has focused on political alliances, and his stop in Mexico is no different. Mexico has traditionally been an ally, but tensions have recently risen over border and immigration policies. Smoothing these tensions and reaffirming Mexico's long-term status as a U.S. ally is the driving motivation behind the U.S. president's visit.

However, though Bush is arriving in Mexico with a largely rhetorical agenda, his counterpart could meet him with a much stiffer proposition.

Since taking office in December 2006, Calderon has aggressively approached his presidency. His presidential campaign called for massive reforms, and he has wasted no time pursuing them. He already has announced plans for a constitutional redraft and a controversial reform of Mexican state-run oil company Petroleos Mexicanos (Pemex) and already has launched a massive multistate offensive to counter narcotics trafficking. Though the attack against drug cartels has not severely impacted their operations, it has won Calderon domestic support; with recent approval ratings ranging from 58 percent to 73 percent, it is clear that Mexicans approve of Calderon's boldness. And since the Mexican government depends on oil money, Calderon desperately needs this approval to push through the Pemex reform.

Bush might not be prepared to meet with a bold Mexican president; former Mexican President Vicente Fox rarely challenged Bush and reveled in a close friendship with his U.S. counterpart. And while Calderon has not disparaged U.S.-Mexican ties, he has made it clear that he is not interested in helping to repair U.S.-Latin American relations, noting that the United States has to "regain respect" in the region.

Mexico has long demanded increased attention -- and a solution -- to the immigration debate. But a visit between Bush and Calderon will have little, if any, impact on the immigration front. Bush's hands are all but tied -- he faces an opposition Congress and a populace deeply divided on the issue at home -- and he is not in a position to settle the immigration issue, much less to do so in a way that Mexico would desire.

Calderon knows this as well as Bush does, and is not expecting a sudden shift in U.S. immigration and border policies. A breakthrough on the immigration front at this point is not plausible, but with this visit Calderon can earn himself a few more approval points at home.

Though Mexico's close relationship with the United States is not likely to change in the near future -- trade, security issues and proximity will tie the nations together indefinitely -- the Mexican government is no longer interested in pushing the U.S. agenda in Latin America. Calderon is ready to be an independent leader, and Bush could find him to be less of an ally than expected.