Mexican President Vicente Fox begins an official state visit to the United States on Wednesday, hoping to make progress with President Bush on an agreement to legalize Mexican migrant workers. But the expectations for such an agreement have been lowered considerably.

President Fox has made his nation's migrant workers one of his major concerns. Realizing that a proposed amnesty for the three-to-four million Mexicans living illegally in the United States would be politically impractical, he is focusing on a guest worker program. Through this program a much smaller group of Mexicans would gain temporary legal status.

But Bush administration officials say devising such a plan and getting it approved by Congress will take some time.

Even if nothing concrete comes out of this week's encounter, Mexican political analyst Sergio Sarmiento says President Fox will score political points at home. "Many Mexicans believe that what the president [Fox] has done so far is actually quite commendable," he says. "The fact that he managed to put the issue of immigration on the agenda between the two countries, when it was something the United States had always rejected, that, in itself, is important."

Mr. Sarmiento says Mexicans realize that President Bush is unable to push either an amnesty or a guest-worker program through Congress without first addressing concerns raised by his own people. Many U.S. citizens fear that granting legal status to Mexican migrants will create a burden on health and social service programs. But Sergio Sarmiento says rules could be established to prevent that.

"Mexican guest workers or Mexicans legalized under an amnesty program might be prevented from resorting to certain social services for awhile. There might be ways of going around it," Mr. Sarmiento says. "The way it is right now, in fact, it is exactly the opposite. Mexican illegal workers contribute to the Social Security system but get no benefits."

Mr. Sarmiento says most undocumented workers are afraid to claim benefits for fear of being caught and deported.

The Reforma newspaper columnist says President Fox has been right in calling his nation's migrant workers heroes, because they have, in many cases, risked their lives going north of the border seeking work. They have helped their families back home and the Mexican economy by sending back billions of dollars a year in remittances.

Mr. Sarmiento argues that they have also contributed significantly to the U.S. economy by taking jobs most Americans do not want.