By Javier Lizarzaburu
BBC Spanish American service
"We are powerful enough to make a difference," says Guadalupe Gomez, talking about the influence migrants have in Mexican politics.
Originally from the Mexican state of Zacatecas, he's lived north, in the US, for more than 40 years. He is currently president of the Federation of Zacatecan Associations.
More Zacatecans live in LA than in Zacatecas
The migrants' influence comes with the massive amounts of money they send back home.
Despite the relative stagnation of the US economy, this flow of money keeps growing, according to recent data. In 2003 it increased by 35% - the total amount sent that year to Mexico was more than $13bn.
Remittances from Mexicans in the US have become one of Mexico's most important sources of income - second only to oil and surpassing the traditional tourism industry.
According to Roberto Suro, director of the Pew Hispanic Center in Washington "remittances have probably benefited Mexico more than Nafta" (the North American Free Trade Agreement between Canada, the US and Mexico).
The flow of money from the US to Latin America largely exceeds the money from foreign aid that the region receives.
For many, remittances have become a form of foreign aid that helps the families back home to alleviate poverty, spur investment and achieve higher standards of living.
But critics argue that dependence on remittances can impair local initiative and create no incentives for people to move forward.
However, the issue is not just about families anymore.
Remittances are fast becoming a new phenomenon, influencing foreign and domestic policies in different countries, including the US - the main source of remittances worldwide.
Experts say the recent immigration proposals submitted by US President George W Bush, to allow migrants to work legally in the US for a limited number of years, are a direct response to the growing influence of Latinos in that country.
For Mexico's President, Vicente Fox, the issue was paramount during his electoral campaign.
He made migration a cornerstone of his political agenda. He even called migrants the new "heroes".
Quite a change from the days, not so long ago, when those who chose to live with "the enemy" - as they used to call the US in many parts of the Mexico - were called "traitors".
The Mexican state of Zacatecas, once a place rich in silver but now one of the poorest areas in the country, is illustrative.
More Zacatecans live now in Los Angeles than in the city of Zacatecas.
The Mexican migration issue is high on the agenda for Bush and Fox
The State Governor, Ricardo Monreal, acknowledges that "their economic influence is huge and their political clout as a consequence of that is huge too".
"It is thanks to them that I became state governor," says Mr Monreal.
Remittances also have social and human implications.
In the village of Jomulquillo, a couple of hours from the city of Zacatecas, what hits you as soon as you arrive is the silence.
One of the few locals remaining there says that at the moment there are 80 people living in the village - 300 live in Los Angeles.
With the empty houses, the closed windows and locked doors, this feels like a ghost town.
But the pain of families being separated is somewhat compensated by these remittances that, in the case of Zacatecas, not only help the relatives but also their villages of origin.
As part of a new strategy, the Mexican authorities have decided to match the money sent by migrants with local, regional and federal money, in order to build roads, schools and medical centres.
From being called "traitors who chose to live with the enemy", Mexico's emigrants have now gained a level of influence and respectability unheard of in the country.
Saca: Said to have won El Salvador's polls with remittance message
According to Guadalupe Gomez "a lot of politicians are taking notice of our influence". And, he adds, they have to do more to make migrants participate in the decision-making process.
It is not surprising therefore that last year, in a historic move, the Zacatecas' state legislature voted in favour of allowing migrants living in the US to stand for political office.
Similar things are occurring in other Latin American countries.
The recent elections in El Salvador show just how much this issue is affecting politics.
Experts say that the right-wing Tony Saca won the elections largely due to last minute television ads warning that a victory for the left-wing candidate would have a negative impact on US-Salvador relations.
One consequence of this, the ads warned, would be massive deportations that in turn would put remittances at risk.
Analysts believe that because nearly 30% of the population depends on the money sent from the US, this twist in the electoral campaign became a decisive element in Mr Saca's victory.
If remittances continue to grow as they have in the last few years, migrants are likely to become crucial players in the politics of their countries of origin and not only in the economy.
How about the US trying to alleviate economic tensions in Mexico and Latin America? That way there wouldn't be a huge flux of immigrants which in turn would help out their governments. Then it'll be one less problem for the US to worry about and one less problem for the Latin American governments to worry about.
Dr Karl Endri Petrela, Summit, New Jersey, USA
This is not right! The US is slowly being invaded by Latin America and everyone is too busy being politically correct to stop it. They bring drugs across the border and send dollars out of the US economy. The US just doesn't have room for any more people. I'm not racist but this isn't right and it has to stop.
Shawn, Flushing, USA
It is highly unfortunate that many of those Mexicans living and working in the US do not appear in the official figures of the US statistics due to their illegal status. This situation greatly affects their living conditions in that country, including wages, access to education and health care. If the US government made an effort to legalize all these illegal immigrants, which greatly contribute to the US economy, the remittances to Mexico will grow considerably, becoming maybe the first source of income to the Mexican economy.
Guillermo Mendoza, Montreal, Canada
$13bn is nothing on what the real cost of the migration is. 25% of the inmates in US prisons are Mexicans. There are reports of Mexican Federal Troops shooting into the US to protect Drug Lords. The US is under invasion, and sometimes the border area looks like a war zone.
Steve Green, Holly Springs, NC, USA
The American dream is over, if you work hard you can make money in your own country.
Ítalo Cavalcanti, Fortaleza, Brazil
I think money sent back to Mexico from the US is draining our economy here in Los Angeles. Immigrants are using all the state and local services while at the same time sending their money back home instead of spending it here. This is one of the reasons why California has a large deficit.
Fred, Los Angeles, USA
Even in Pennsylvania, which is a long way from the Mexican border, small restaurants have opened run by a large family group from Guadalajara. The food is fantastic and the staff are hard working and very congenial. As is typical, the shops are open seven days each week from 11:00 to 11:00... try beating that for ambition! Now they are developing a chain of restaurants throughout many smaller cities.
Sharon Schafer, Pennsylvania, USA
Maybe if the US (and other nations) would relax our immigration policies, workers could bring their whole families with them, and that $13bn could stay here in the States.
Matt Johnson, Mobile, Alabama, USA
As a Mexican living in the United States I have experienced how, Mexican immigrants, in fact influence Mexican politics. When President Fox was being elected many of the Mexicans in Chicago highly supported him and usually called their relatives to tell them that he was their best choice. Particularly because Fox has highly supported the idea of allowing immigrant to vote from abroad and also because many were upset that it was the economic environment created by the previous party, the PRI, that made them emigrate in the first place.
Jose Galixto, Madison, Wisconsin, USA
Mexicans who live and work in the USA have never been criticised as your report suggests. It is accepted by just about everyone that they go north to make money. The people who are criticised are the ones who cross over as it were and become American nationals. They are known as pochos in Mexican Spanish and, yes, they are widely disliked. So, making money in the USA is OK, but giving loyalty to the place is still frowned upon.
Ken Bell, Mexico City
I think it's very bad that our country depends so much on remittances from our "paisanos" in the US. I think that our country should impulse the national industry and market, instead of depending on foreign money. Every nation should be self sufficient, and even the rich ones aren't.
Ernesto Lomelí, Tijuana, Mexico