By Julian Miglierini
BBC News, Mexico City
Immigration reform is back up the US and Mexican political agenda
Ask Mexicans what their President Felipe Calderon should be talking about during his state visit to Washington this week and you get the same answer over and over.
Migration, migration, migration.
The destiny of the millions of fellow nationals who live, legally or illegally, north of the border is the issue closest to their hearts: most Mexicans have a friend or relative who is trying to live the American dream.
It was already a crucial issue in the bilateral relationship, but has been brought right to the top of the agenda with a new law in the state of Arizona.
This requires police to inquire into the immigration status of any person they have stopped if there is "reasonable suspicion".
'Intolerance and hate'
Many Mexicans consider Arizona's law to be racist, since they fear that anyone who looks Hispanic will be stopped and questioned by the Arizona police when the law comes into effect in a few weeks.
President Calderon, one of the toughest critics of the new law, is expected to raise the issue during talks with US officials.
"Criminalising immigration, which is a social and economic phenomenon, opens the door to intolerance, hate, and discrimination," Mr Calderon said after the law was passed.
President Barack Obama visisted Mexico in April 2009
He could use similar words in his meeting with President Barack Obama, who has also criticised Arizona's legislation, and during his address to a joint session of the US Congress.
But the criticism goes beyond the specific Arizona law and aims also at preventing other US states from adopting similar measures.
More important, many Mexicans believe, is that the US approves much-delayed federal immigration reform that could clarify the situation of the millions of Mexicans who live in the US illegally.
While Mr Calderon's championing of the debate about migration is born of legitimate concern, his focus on the issue also has elements of political opportunism, some believe.
"The law in Arizona is an opportunity that the Mexican government is using to talk about an issue that is not drug-trafficking," Leticia Calderon, a sociologist, told the BBC.
"And it's ironic, since President Calderon, in the early days of his mandate, had tried to lower the profile of the migration issue to focus on other items."
Indeed, over the past few years the bilateral relationship had been dominated by Mexico's war against the drug cartels that have a stronghold in some regions of the country and along the US-Mexico border.
Thousands of Mexican police and troops are fighting the drug gangs
Washington fears that the violence, which has killed more than 22,000 since Mr Calderon launched a military offensive against the drug gangs in late 2006, could spill over into US territory.
At the same time, Mexico has insisted that drugs consumption in the US and the flow of guns from the US into Mexico fuel the conflict; hence, it expects more active US collaboration.
The US has been directing funds towards Mexico through the multi-million dollar Merida Initiative, launched during the Bush administration, to help train and support Mexico's law enforcement agencies.
President Obama has spoken of the need to curb US drug consumption and stem the smuggling of guns from the US to Mexico.
"There is a notion of shared responsibility in the drugs conflict that the current US administration has promoted and marks a substantial change from previous governments," Francisco Abundis, a Mexican public opinion analyst, told the BBC.
The two countries have many issues uniting - and dividing - them
However, as Mr Calderon's visit will no doubt highlight, collaboration needs to go beyond words.
"To actually quell the drug violence that plagues Mexico, we need a long-term and sustained effort for police and judicial reform," Joy Olson, head of the Washington Office on Latin America, a progressive think tank based in the US capital, said recently.
"This is costly and a hard sell politically, but nothing else will work," Ms Olson said.
While migration and drug-trafficking seem set to dominate discussions, there are also key economic issues for the two nations, including a dispute over allowing Mexican trucks to enter the US.