Now that Spitzer has rejected the idea, Clinton has managed to discover what her position on driver’s licenses for illegal immigrants actually is (today, she’s against them). In the end, this is the smart move–expose yourself to some scorn from pundits and reporters now in exchange for taking the safe (and, as it happens in this case, correct) position and avoiding bigger trouble later. Obama, notably, had already come out in favour of the idea, so on one of the more prominent differences between them Obama is on the wrong side of the issue not just nationally but also among Democratic voting blocs that he already has trouble winning over.
P.S. Her opponents will try to make this into a question of her credibility, as well they might, but this will not end up making much of a dent. A lack of credibility and being on the wrong side of this issue could have hurt her substantially. Now she is protected, and she can probably spin it with some prattle about having “thought long and hard” about a “difficult issue,” which, in our bizarre political culture, somehow makes her seem more responsible and intelligent than the people who actually say what they think the first time around.