I just had a politically conservative friend send me a video about voter ID. In this video - which seems to be a legitimate undercover operation (as opposed to the clowns who committed fraud trying to spy on my Senator Landrieu's office) - the reporters asked the guards outside of various organizations that are railing against voter ID if they needed an ID to enter. Of course, the answer was yes for all of them.
This helps to bring out a good point that folks on the Left are not too keen about - i.e., the rule of law. It should be a necessity that when someone does a citizen act - e.g., serve on jury duty, file a court case, etc. - he should prove that he is who he says he is. The argument that folks should be allowed to vote without the ID strikes a lot of folks as similar to the idea that folks who are illegal aliens should just be allowed to stay. Not a whole lot of folks in the middle think that is fair (although the situation with children, which is addressed by the DREAM act is a little different), and also think that folks who want to vote should have to show an ID as well. The fact that more voters on our side are less likely to have an ID is not this issue.
The proper policy with respect to voter ID is to make the system Constitutional - i.e., anyone who wants to vote should be guaranteed the right, without having to pay anything (i.e. poll tax.) This means that if a state wishes to have a voter ID law, then the state needs to give out proper voter ID's at the same time that folks are registering (or allow the IDs to be gotten after registration, etc.) And if a birth certificate is required, then that should be free of charge as well, and facilitated at the voter registration office. This is probably the main reason that the conservatives could not defeat the motor-voter law, since it actually helped folks to get the ID to vote.
To address the issue of old folks, or other folks on the margins, who were born before a birth certificate, there should be some realistic process that they can follow to get some type of a documentation in lieu of a birth certificate, used only for voting. For college kids, or other temporarily transplanted folks, there should be the right to get a separate voter ID that does not require the relinquishing of the home state driver's license. (I know about this as I tried to get just the ID - not the driver's license - when I was a Katrina refugee in Colorado, and could not get one so long as I held on to my Louisiana driver's license.) And for infirmed folks, there should be a way to make sure that they are validated as well.
There are probably other situations I have not thought of, but I think everyone gets the gist of it. Push for the law to be as fair and encompassing as possible, and if the Republicans bitch because of the cost, push it right back in their face by saying, "OK, let's just keep it the way it was."