The New York Times points out another reason why a bipartisan group in the Senate is reportedly eyeing a decade-long path to citizenship: Because the Congressional Budget Office uses a 10 year scoring window, any additional cost of providing benefits to new citizens wouldn't appear in the law's cost-estimate:
And as a side benefit, waiting a decade would mean that the costs of the overhaul would not kick in until the second decade because illegal immigrants do not qualify for government benefits until after they earn green cards. That means the 10-year cost estimates by the Congressional Budget Office would not include the expense of those benefits.
That's not to say that the costs would necessarily outweight the benefits. If anything, the opposite might be true: As TPM's Brian Beutler pointed out recently, when the CBO scored a 2007 immigration reform plan, it found (along with the Joint Committee on Taxation) that providing benefits to newly legalized immigrants would cost $22.7 billion over a decade. Yet the same law was scored as increasing revenue by $48.3 billion over the same time frame.
Of course, you don't need to look at tax revenues to see the economic benefits of increased immigration. It increases a nation's overall economic performance, improves the lives and economic standing of immigrants, and, on average, helps native-born citizens as well.
But the Senators working on the immigration overhaul don't seem to want to talk about the potential benefits. Instead, they're stressing, as the Times also notes, that "the legislation would require that the existing immigration backlog be cleared up and the border be secured before illegal immigrants receive green cards or citizenship" and that immigrants would have to pay fines and back taxes before becoming eligible for legal status. It's a remarkably timid, defensive approach that puts the fears of immigration critics ahead of efforts to make a case for the benefits of more immigration, sooner rather than later.