SAN DIEGO –A Chula Vista teacher’s “endless” wait to become a US citizen has stretched nearly three decades.

As the debate over immigration reform continues, all sides seem to agree, a pathway to citizenship for the country’s 11 million undocumented immigrants should start behind those who are legally waiting to become a citizen.

“It’s an endless line,” said Tania Guzman, one of an estimated 4 million immigrants currently waiting to get a green card, a required step to become a US citizen. “There are just not enough visas.”

Guzman lives in the country legally thanks to a work visa she is forced to renew every year, “It costs me thousands of dollars,” said Guzman.

Immigration law experts said Guzman is victim to a decades-long backlog in the nation’s immigration system.

Depending on age, family and marital status, those who qualify to apply for a green card fall under a set of categories, which determine your place in line.

“This is why people say that our system is broken,” said immigration attorney Lilia Velazquez.

Over the years, Velazquez has seen hundreds of cases like Guzman’s, including some with waits as long as 100 years.

Velazquez said the problem is there aren’t enough green cards to satisfy the demand.  As the demand grows, so does the wait.

“There are some people who’ve been waiting in line within a particular category that will never be able to get their green card at the rate that those numbers are moving, which is they’re not moving at all,” said Velazquez.

Velazquez and many other immigration experts are worried about what this means for immigration reform and the 11 million undocumented immigrants living in the US, hoping for a spot at the end of the line.

“It will be a pathway to infinity, a pathway to nowhere, unless Congress can first figure out how to deal with the backlog of those already in line,” said Velazquez.