Congressman Raul Grijalva and six members of Congress plan to visit Tijuana, Mexico this weekend to bring attention to the plight of deported military veterans.

Grijalva reintroduced H.R. 1405, which would establish a visa program that allows deported veterans who meet certain requirements to re-enter the U.S. as lawful permanent residents.

It's difficult to know exactly how many U.S. service members have been deported. Last year, the ACLU of California published a report detailing the stories of dozens of military veterans who have been deported or who face deportation proceedings.

They were brought to the U.S. as children and teenagers before assimilating into American life. They served in the armed forces, established careers, raised families and ended up entangled with the law for crimes ranging from tax evasion to theft and drug possession. Once in the criminal system, many of them were deported by federal immigration court.

California Gov. Jerry Brown recently pardoned three service members facing deportation proceedings.