Immigration reform: How many new immigrants are we talking about?

These may seem like straightforward questions: How many new permanent residents of the United States will there be every year, if the Senate’s bipartisan legislation on immigration reform becomes law? And how many new workers would the plan inject into the American economy, exactly?

The problem, at least for the moment, is that even those involved in crafting the immigration reform legislation don’t know the answers.

“Nobody has a number that is based on the bill right now that’s accurate,” said Lynn Tramonte, deputy director of America’s Voice Education Fund, a group that supports the reform effort, in a conference call with reporters. “This bill is extremely sophisticated ... it’ll take a bit more [analysis] to get a specific number about how things will change.”

A Senate Democratic aide involved with the drafting of the bill echoed that assessment, as did a Senate Republican aide outside the process.

It’s a fundamental issue, yet to be resolved, even as Senate Judiciary Chairman Patrick Leahy (D) of Vermont looks to move the bill through his committee in as little as two weeks' time.

Supporters and detractors agree that that, should the bill become law, they expect legal immigration to boom over the next 10 years.

Pro-reform analysts say that’s a good thing: The bill is replacing illegal workers with legal ones, these advocates argue, thus allowing American employers legally to meet legitimate business needs and uniting families kept apart by poorly fashioned immigration laws.

“You’re having to play catch-up for 20 years of neglect of this system,” says Mary Giovagnoli, director of the Immigration Policy Center and a former aide to the late Sen. Edward Kennedy (D) of Massachusetts during the 2007 immigration reform effort.

Without creating a functional (and larger) legal immigration system, they say, the lures for illegal immigration will remain.

But the only hard numbers being thrown around are from immigration reform critics like Sen. Jeff Sessions (R) of Alabama and low-immigrant advocacy groups like Numbers USA, who believe the current Senate bill could double the number of foreigners who gain legal residence over the next decade and add scores of low-skilled workers to an economy with persistently high unemployment.

“Wages have not gone up for the working American over the last 15 or 20 years. My Democrat colleagues have hammered that for a long time, not so much lately,” Senator Sessions said at a hearing earlier this week. “So we have high unemployment, particularly among low-skilled workers, and we have these highly capable people ... arguing for more low-skilled workers. And I don't see how that can be justified at a time we have high unemployment.”

Today, the US allows about 1 million foreigners to become legal, permanent residents every year. The majority of those come by way of family connections, with about one-fifth entering for employment reasons and one-tenth coming to the US as refugees or for asylum.

The nation also admits roughly 600,000 more foreigners on temporary work permits, according to an analysis from the Migration Policy Institute of 2012 immigration data.

During the next decade, the Senate bill would completely clear the more than 4.5 million children, parents, and siblings of current American citizens who are waiting in backlogs for family-based immigration. This is a key requirement, said a Senate Democratic aide involved in drafting the legislation, in order to assure that no illegal immigrants gain permanent status in the US ahead of anyone who attempted to enter the country legally.

While the vast majority of the estimated 10 million to 12 million undocumented immigrants in the country now will have to wait at least 10 years to become permanent residents, most will become eligible to work as soon as the secretary of Homeland Security submits a report on how to secure the nation’s southern border – and there are some groups who could become permanent residents sooner.

Some 2 million “DREAMers,” or immigrants brought to the US illegally before age 16, would have a special path to permanent status in five years. Some of the roughly 1 million agricultural workers in the US illegally would also have a path allowing them permanent status between three and seven years.

The bill would also exempt wide swaths of people currently counted against immigration caps from any limits: The spouses and children of legal permanent residents would be allowed to come to the country on an unlimited basis, for example.  

Thus, some combination of, perhaps, 7 million DREAMers, agricultural workers, and the newly legalized family members of current US citizens will be able to petition for their family members, further swelling legal immigration by an indeterminate amount.

And beginning five years after the bill is enacted, the Senate measure would create a new “merit based” immigration category with 125,000 initial visas (a figure that could rise to as many as 250,000 over time) that includes a path to a green card and citizenship, adding more than half a million potential new permanent US residents before the decade is out.

A new low-skilled worker program that would offer some of those in the program a path to permanent residency would begin with 20,000 visas in the year 2015 and gradually scale up to 75,000 visas during the next four years.

This is in addition to a beefed-up agricultural worker program and expanded visas for high-skilled workers (from 65,000 to 110,000) and exempting many extremely high-skilled foreigners – those with doctorate-level education, certain physicians, and business executives, among others – from immigration caps altogether.

On the other hand, the bill closes some avenues of immigration, such as the 55,000 annual visas available in the diversity visa lottery and the 65,000 visas available for siblings of US citizens.

When immigration skeptics like Sessions and Roy Beck, the head of Numbers USA, add up the figures, they see a 50 percent increase in US immigration on an annual basis and as many as 20 million more new green cards within the next dozen years than would otherwise be authorized – and perhaps as many as 30 million more, according to a Republican aide.

Why is it so hard to calculate the bill's exact effect? Immigration law is very, very complex.

The new Senate employment-based programs, for example, would flex with employer demand, in some cases. Moreover, the fact that some temporary-worker categories, such as high-skilled visas, can eventually lead to green cards makes immigration flows in any given year difficult to ascertain.

While immigration reform adversaries can craft scenarios in which new immigrants petition for multiple family members each and bump the figures up significantly, Democrats point out that employment-based immigrants (toward whom future immigration flows will be more heavily tilted) are less likely to do that.

Because the figures flex over time, however, immigration advocates are reluctant to offer an exact number – and expose themselves to political pyrotechnics from Beck and Sessions.

“Part of the reason that we’re reluctant to give specific numbers is because it is so complicated, and we’re very aware that Numbers USA and all those other guys are going to have a field day with that,” says Ms. Giovagnoli. “We’re trying to be thoughtful about how we calculate those numbers.”