Part II, a little late
EDUCATION The No Child Left Behind Act relies on broad and potentially misleading measures to guess at school quality, because there is no way to track individual children from grade to grade and see how they progress. School districts have no way to know which students quit school and which ones have just moved across town, which means federal accountability schemes have no way of factoring in dropout rates. A national ID database could allow for more honest accounting.
This one involves more reading between the lines. Inherent (but unspoken) is the fact that you will have this national ID even as a child. So there will be some kind of database that tracks you, from birth, and includes your academic performance and possible disciplinary measures. All tied to you. Talk about a permanent record! Honestly, how many agencies do they want to have access to these ID records?
I also seriously, seriously doubt that all school districts have no way of knowing who has dropped out and who has moved. And I wonder what will happen to the hundreds of thousands of children of illegal immigrants? I guess they'll just not get educated. Ooh, that's a good idea. No better way to lift people into contributing members of society than denying them an education.
SOCIAL WELFARE The tangle of agencies that work with the disadvantaged have no good way to share data. It was only a decade ago, for example, that researchers began proving that federal spending to reduce homelessness cuts costs in the prison, health care and welfare systems. A national ID database might lead to better allocation of resources, and quicker responses to emerging needs.
Those are some mighty flimsy connections, there, John. Q. Asshole. We only recently proved that more federal spending to reduce homelessness cuts costs in welfare? And therefore an national ID might lead to quicker responses to emerging needs? Huh? Again, if the point is that knowing who is involved in different programs aids efficiency, I still fail to see why the individual and discrete number we all already have - the one tied to our government financial business already (I'm looking at you, Social Security number!) wouldn't work for this.
IMMIGRATION A national ID would help Immigration and Customs Enforcement shift its emphasis off impoverished undocumented workers and onto the often unscrupulous businessmen who hire them. For now, if a businessman, a farmer or a labor contractor gets pulled over driving a truckload of illegal immigrants, they can play dumb  even if they sold the workers their fake ID's. "The workers aren't going to say anything, because they need the job," says Brian Poulson, the customs enforcement chief for California's Central Valley. "Am I going to get any material witnesses? No." The government's only real option is to arrest the laborers. "It's only the little guy that gets hurt," he says.
Um. Right. Because I think we are all totally 100% sure that these new ID cards will be impossible to forge. Those old state IDs? Nothing to it. But the new ones will be the most perfect things ever created. Maybe we can even get them tattooed or implanted!
As a parting thought, keep in mind that it's a pretty damn short step from having a national ID to being required to carry said ID on you at all times to being legally compelled to produce said ID if stopped and requested to by the authorities. A tiny little step from here to having to carry it with you at all times, under penalty of law. Is that where you want to go?