These 200,000 new registrants were just flagged because they didn't match records in other government databases (driver's licenses and SSNs). It could be nothing more than mismatches due to different ways of typing the address (do you put "Street" or "St."?) or data entry errors, or legit mismatches like people who recently moved or had recent name changes.
The point of the decision, as I read it, is that the data matching law wasn't written to determine voter eligibility. Other than the matching failure, the GOP offered no evidence of fraud in these cases.
I was discussing this on a neighborhood list yesterday and today. Someone was trying to argue that these databases aren't so prone to error. Funny--I'd just made 3 phone calls to AT&T to try to get them to stop calling me (by automated machine--not a human) about my overdue wireless bill. . . for the simple reason that I am not now and never have been an AT&T wireless customer in my entire life. Just after I posted that this morning, I got yet another call from the machine!
Sorry, I just don't believe databases are so infallible!
On the other hand, I think they should verify as many as they can, and any that look bad upon closer look should be made to cast provisional ballots (if they show up to vote).