As president, Hillary Clinton would support the automatic granting of green cards, or permanent residency, to foreign students who earn advanced STEM degrees in the U.S.

Clinton, the presumptive Democratic presidential nominee, said she wants the U.S. to "staple" green cards to the diplomas of non-citizens who earn master's or Ph.D. degrees in STEM fields (science, technology, engineering or math) "from accredited institutions."

Clinton outlined her plan in a broader tech policy agenda released today.

This agenda is big on improving computer science education and is modeled after some of President Barack Obama's efforts, such as training 50,000 computer science teachers in the next 10 years. But the topic that may get the most focus is immigration.

Clinton's "staple" idea isn't a new. It's what Mitt Romney, the 2012 GOP presidential nominee, supported. It has had bipartisan support in Congress.

Broadly, a diploma/green card policy would allow new graduates to bypass temporary H-1B work visas and move from student visas to green cards. The graduates will need to have jobs lined up in order to qualify, and the proposals may require a waiting period. Clinton's plan has no specifics.

Even so, the idea is controversial. Critics will say the provision would be hard to control, could foster age discrimination and is likely to put pressure on IT wages.

Ron Hira, a public policy professor at Howard University, testified earlier this year that such a program "will create perverse incentives in both the labor and educational markets." Employers, he said, "will be incentivized to replace their older incumbent workers with cheaper fresh graduates, fueling age discrimination."

If a "staple" policy went into effect, colleges would likely recruit foreign students into advanced degree programs with the promise of green cards.

"Given that master's [programs] are short in duration (as little as 12 months), and have little oversight from outside bodies (no specialized accreditation process for most), this provision will make it inexpensive for foreigners to purchase green cards from a variety of universities," said Hira during Senate testimony delivered earlier this year.

Former U.S. CTO Todd Park argued for a staple provision while at the White House. "Today's advanced STEM graduate could be tomorrow's world-class, world-changing scientist," he wrote in a blog post.

The tech agenda unveiled by Clinton doesn't address the H-1B visa program. Clinton has been silent on what she would do about the temporary work visa; her comprehensive immigration plan doesn't address it either.

Donald Trump, the presumptive Republican presidential nominee, has said in his platform that before green cards are issued to foreign workers "there will be a pause where employers will have to hire from the domestic pool of unemployed immigrant and native workers."

But Trump, during a GOP presidential debate in Detroit in March, seemed uncertain about how to handle international students who graduate from U.S. schools.

Foreign students will go to Harvard, Stanford and Wharton and "as soon as they're finished they'll get shoved out," Trump said. "They want to stay in this country. They want to stay here desperately, they're not able to stay here. For that purpose, we absolutely have to be able to keep the brain power in this country."

Norman Matloff, a computer science professor at the University of California at Davis and a longtime H-1B critic, said: "It is a shame that both Trump and Clinton have bought into the industry lobbyist line of a STEM labor shortage. There is no data evidence for that, and anyone can see wages have been flat, counter to the claim of a shortage."

Matloff argued that a staple law "would reduce job opportunities and wages for new graduates and especially for older workers."