With all the frantic debate being whipped up about the 12 million undocumented immigrants in the United States, another group of immigrants is quietly making plans to return home — and taking its technology/entrepreneurial skills with it.

An estimated 20 percent of skilled immigrants in the U.S. said they are considering or have decided to return to their home countries or migrate to other countries because of the broken U.S. immigration system, according to a new study by the Kaufman Foundation.

Many have been waiting with green cards in hand for years to get permanent resident visas, only to lose their place in line when their company is bought out.

They can't accept promotions, raises or seek new job opportunities because that would require them to reapply for visas and go to the back of the line, according to the foundation's recent study "Intellectual Property, the Immigration Backlog and Reverse Brain Drain: America's New Immigrant Entrepreneurs."

Many are the same immigrants who came to the U.S. during the heyday of Silicon Valley and helped pioneer many of the technological advances that we take for granted on a daily basis.

Another report estimates there are more than 1 million of these immigrants in the U.S. Some have decided to return to their homes in India and China, areas that are enjoying booming economies, so that they can start their own companies, which may eventually compete with U.S. businesses.

Many first came here because the number of highly skilled U.S. workers was not keeping pace with industry demands. That is still a problem and will only grow worse if this generation of skilled immigrants is allowed to leave — and if more emphasis is not placed on educating potential U.S. workers.

Besides India and China, many of those highly educated legal immigrants also come from the Philippines and Mexico.

Previous studies have discovered that immigrants founded half of the technology and engineering companies in the Silicon Valley between 1995 and 2005, with those immigrants starting about 25 percent of those companies nationwide during the same period.

Nationwide, those companies employed 450,000 workers and generated $52 billion in revenue in 2006. That's quite a chunk of payroll dollars and taxes that could go to everything from paying for police and fire services, roads, schools and other taxpayer-supported programs.

Scientists, engineers, doctors and researchers are some of the 1 million immigrants who are competing for the 120,000 permanent U.S. resident visas each year.

"The United States benefits from having foreign-born innovators create their ideas in this country," said Vivek Wadhwa, a Wertheim fellow with the Harvard Law School who led the study. "Their departures would be detrimental to U.S. economic well-being. And, when foreigners come to the United States, collaborate with Americans in developing and patenting new ideas, and employ those ideas in business in ways they could not readily do in their home countries, the world benefits."

The study was also conducted by researchers from Duke University and New York University.

Many of the immigrants say the current anti-immigrant rhetoric is having an impact on their decision to leave the U.S.

Leigh Plimmer, a CPA from Atlanta who was born in South Africa, told ABC News that the current immigrant debate has painted a false picture of all immigrants as "illegal, lazy, criminal, unbeneficial and parasitic."

Sacheen Kamath, a computer engineer whose work led to the development of a next-generation networking product, is considering leaving the U.S. because his wife can't work because she has to be listed as a dependent and he has been forced to reapply for a permanent visa because his firm was so successful it was purchased by another company, which has a research center in India.

Kamath is considering moving to India and working at that center.

"I have begun to hate my work and my life in the U.S.," Kamath told ABC News. "I think that it is better to be king in a third world country than a helpless immigrant in a superpower, developed one."

— Frank Moraga is The Star's director of diversity and general manager of Mi Estrella, The Star's bilingual weekly newspaper. He can be reached at fmoraga@VenturaCountyStar.com.