ID check for voting--why not?

I looked at a blog post by Michelle Malkin today, referring to a party-line vote on a voter ID law.

Malkin posted the vote breakdown, and not a single Democrat voted in favor of requiring a voter ID. I surmised there must be some principled (or supposedly principled) objection to such a law.

So what is it? I think this piece in Slate (by Richard L. Hasen) probably sums it up:

Republicans defend voter-identification laws as necessary to combat voter fraud. But Democrats and civil rights organizations see these laws as a way of gaining partisan advantage—because it's the poor who will have a more difficult time securing voter identification. Poor people tend to drive less (meaning they won't have a driver's license, which is the most common form of ID), and they may not have the money to secure certified copies of documents, such as the birth certificates necessary to obtain a state-issued voter identification. The poor also happen to be more likely to vote Democratic.
(Slate)

There's at least a kernel of a reasonable argument, there. Requiring voter ID might cause some potentially legitimate voters some difficulty in casting their votes. And it is reasonable to weigh the potential benefits of the law against that potential drawback.
The Slate story takes a stab at doing just that.

More important, it's not clear what the nonpartisan object of this exercise would be. Beyond a few isolated instances and anecdotes, there is precious little evidence of the kind of voter fraud a state voter ID card requirement would deter. I am aware of no studies finding evidence of any kind of systematic or serious problems with voters casting ballots in someone else's name, or with voters registering and actually voting using fictitious names. There is a great deal of registration fraud—such as when "Mickey Mouse" registers to vote. That problem is an artifact of paying bounty hunters to collect completed registration forms; some of those mercenaries will falsify information on registration forms. But, invariably, Mickey declines to vote on Election Day, so where is the fraud?

Should we accept the notion that registration fraud is limited to voter registration mercenaries?

At least eight people who died well before the November general election were credited with voting in King County, raising new questions about the integrity of the vote total in the narrow governor's race, a Seattle Post-Intelligencer review has found.
(seattlepi.com)

In principle, couldn't I register as three or four recently dead people near voting district, and then vote for each of them? How much would I have to know in order to fake a registration form? Here's what California currently requires.

6. ID Number When you register
to vote, you must provide your California driver’s license or California
identification card number, if you have one. If you do not have a driver’s license or ID card, you must provide the last four digits of your Social Security Number (SSN). If you do not include this information, you will be required to provide identification
when you vote.
(.pdf)

Unfortunately, there are ways to obtain a full Social Security number, which inevitably includes the last four digits. Even more unfortunately, it's not difficult (forgive me if I don't explain how to do it).

So, unless I'm missing something, it should be pretty easy to perpetrate voter fraud by this method, if not others.

As it happens, a number of states have attempted to institute voter ID laws, and have had them struck down as discriminatory (apparently following the principle in the Slate piece that notes that poor folks might have more trouble securing identification).

The objection holds that the state has not justified the law by demonstrating a pattern of voter fraud that the measure would address. But how do you obtain evidence of this type of fraud, and do you really need more than the repeated examples of dead people voting?

It seems that the objection is a non-starter. An obvious loophole justifies correction regardless of any established pattern of abuse. Leaving the loophole in place cannot help but discourage confidence in the legitimacy of our voting systems--even more so than potentially discouraging poor people from voting because they could not afford to obtain identification.
***

The proposed state law in Georgia, I'll add, was amended to subsidize the costs of identification for poor people. It remains to be seen whether or not the courts will find that the mere requirement that would-be voters take one step beyond registering to vote discourages voting to the point that the law is unconstitutional.

I do have a proposal that might help. Take a thumb-print with every vote that is cast without an ID. The thumb print goes on the registration list and not the vote, so the vote remains anonymous. The thumb print provides a potential assurance that the same voter isn't voting in multiple locations. Not only that, it serves as evidence once a suspect is found.
It's common practice in banks, and shouldn't be expensive to implement. Lawmakers can then decide how to best use the system to prevent or punish voter fraud.
***


Identification requirements on the Federal form, which may be used in any state:

Federal law requires that states collect from each registrant
an identification number. You must refer to your state's specific instructions for item 6 regarding information
on what number is acceptable for your state. If you have neither a drivers license nor a social security number,
please indicate this on the form and a number will be assigned to you by your state.
(.pdf)

Here's the relevant portion of the form used in Michigan:

ID Number check applicable box and provide appropriate number
❍
I have a state issued driver license or personal ID card #
State
❍
I do not have a state issued driver license or personal ID card. The last four digits of my Social Security Number are
❍
I do not have a state issued driver license, a state issued personal ID card or a Social Security Number.
An ID number will be assigned to you for voter registration purposes.
(.pdf)

The Michigan form makes it appear that it is possible to register to vote without having a Social Security number. I'd been under the impression that all U.S. citizens of voting age had assigned Social Security numbers. Evidently that isn't the case.