Silicon Valley's long crusade to break open doors to America for foreigners with key technology skills hinges on a political battle in Washington over broader immigration reform.

For more than a decade, the tech sector has been struggling to get more visas and green cards for immigrants with engineering, math or science skills.

While Silicon Valley has been largely backing reform-minded Democratic candidates including President Barack Obama, Republicans have begun paying attention to broader immigration reform, an issue dear to US Latinos.

"The election happened and the Republicans took a shellacking from Hispanics," said Robert Atkinson, president of the Information Technology and Innovation Foundation think-tank in Washington.

"It was a wake-up call," he continued. "A comprehensive approach to immigration reform became viable."

The new political landscape hobbled efforts to push through stand-alone legislation focused just on high-skilled workers.

"High-skill immigration is definitely being held hostage to broader reform," Atkinson said.

Stanford University fellow and Singularity University vice president Vivek Wadhwa champions STEM immigration.

"Who is behind the US tech boom right now? Immigrants," Wadhwa said. "Just as the US is reinventing itself with a whole range of technologies we are cutting off the circulation in Silicon Valley."

A Republican-backed House bill to expand visas for foreigners graduating from US universities with advanced degrees in science and technology was killed in the Senate by Democrats in the name of broader immigration reform.

"We need visas and a new-and-improved immigration arrangement for Silicon Valley and the high-tech sector, but the only way we will win reform is to fight for top-to-bottom overhaul of our immigration system," Democratic congressman Luis Gutierrez said in an editorial on technology news website TechCrunch.

Gutierrez is chairman of the Immigration Task Force of the Congressional Hispanic Caucus and was responding to comments by Wadhwa, who testified in Washington this month.

Wadhwa claims the two issues are separate.

"Providing citizenship to people who jumped over the border is contentious; it's toxic," Wadhwa maintained.

"In the meantime you are holding hostage the legal, skilled immigrants -- scientists, engineers, doctors -- who the whole world wants."

Reforming the immigration process for the tech industries would mean ramping up the number of H-1B visas, for immigrants with special skills.

Wadhwa said the reform should also change the system which ties those with H-1B visas to specific companies, to allow them to seek better compensation or new jobs, or start their own firms.

"We are basically choking off immigrant entrepreneurship," Wadhwa said.

Microsoft has cited a lack of visas for engineers as the reason it opened a development studio in the Canadian city of Vancouver.

Atkinson said this moves production offshore, and "that is not good for this country."

A stand-alone reform bill by Republican Senator Orrin Hatch would raise the annual cap on H-1B visas to 115,000 from 65,000 and pump the money into STEM (science, technology, engineering and math) education in the United States.

"There is no down side to supporting a good high-skill immigration bill," Atkinson said.

Now, analysts say Republicans and Democrats appear to be looking at a comprehensive measure that deals with high-skilled workers and the millions of undocumented aliens.

"Because our immigration system needs fixing top to bottom, fixing it all at once is the right way to approach things," Gutierrez said.

The strategy could succeed with the help of Silicon Valley companies that believe the only way to get the immigration changes dear to them is to back an overhaul of the system.

"This is critical to America's future," Yahoo! chief Marissa Mayer said in a statement released early this month after meeting with Obama to discuss immigration reform.

"I urge Congress and the president to work together in a bipartisan effort to reform policies on immigration, including meaningful reforms to hiring and retaining highly-skilled talent."

The fact that this is not an election year lends hope for support from legislators who might view immigration reform as politically risky.

"You are always playing the roulette wheel when you predict legislation in Washington," Atkinson said. "But, I think the odds aren't bad for something this year."