

A voter walks past a 'Please Have Photo ID Ready' sign as he enters an early-voting polling place in Little Rock, Ark., on May 5. (Danny Johnston/ AP)

State legislators who support voter ID laws are motivated in no small part by racial bias, according to a new study from the University of Southern California. The study finds strong evidence that "discriminatory intent underlies legislative support for voter identification laws."

The findings raise questions about the constitutionality of voter ID laws, which the Supreme Court affirmed in 2007 on the basis that Indiana's strict law represented a "generally applicable, nondiscriminatory voting regulation." For quick background, these laws require registered voters to show some sort of government-issued ID before they vote -- supporters say they're necessary to prevent voter fraud, while opponents counter that they disproportionately affect elderly, minority and low-income groups. For more, see ProPublica's excellent backgrounder on the topic.

Demonstrating racial bias is not easy -- as I've discussed before, nobody actually calls themselves racists, because much racial bias happens at the subconscious level -- so the USC researchers developed a novel real-world field experiment to test bias among state legislators. In the two weeks prior to the 2012 election, they sent e-mail correspondence to a total of 1,871 state legislators in 14 states. The e-mails read as follows:

Hello (Representative/Senator NAME), My name is (voter NAME) and I have heard a lot in the news lately about identification being required at the polls. I do not have a driver’s license. Can I still vote in November? Thank you for your help. Sincerely,

(voter NAME)

The key to the experiment lies in that voter name field. One group of legislators received e-mail from a voter who identified himself as "Jacob Smith." The other received email from "Santiago Rodriguez." Moreover, half of the legislators in each of these two groups received e-mails written in Spanish, while half received English-language e-mails.

The researchers then measured the lawmakers' response rates to these e-mails. Crucially, in each state in the study, legislators really could have simply responded with a "yes" -- drivers' licenses were not required in any of the states in order to vote.

The researchers found that legislators who had supported voter ID laws were much more likely to respond to "Jacob Smith" than to "Santiago Rodriguez." This gap reveals a preference for responding to constituents with Anglophone names over constituents with Hispanic ones.

There was also an Anglophone preference among legislators who had not backed ID requirements, but crucially this preference was much smaller. This finding held true among legislators who received English-language e-mails, as well as legislators who received Spanish e-mails.

An individual case of non-responsiveness alone isn't evidence of bias. But the significant difference between ID supporters and opponents in the extent of their Anglophone preference provides solid evidence of underlying bias, according to the researchers.

"The fact that legislators supporting voter identification responded so much l to the Latino name is evidence anti-Latino bias, unrelated to electoral considerations, might be influencing these public policies," they write. "The same elites who propose and support legislation to restrict Latino voting rights also provide less non-policy responsiveness to Latino constituents, at least in the context examined here. This means that the quality of representation is poor for many Latino constituents."

More to the point, these findings raise serious questions about the legality of voter ID laws. The Supreme Court's 2007 justification for these laws rests on two pillars.

The first is the notion that voter fraud even occurs at significant levels. Recent research has overwhelmingly debunked this idea: a recent study by political scientists at Stanford and the University of Wisconsin found that "virtually all the major scholarship on voter impersonation fraud – based largely on specific allegations and criminal investigations – has concluded that it is vanishingly rare, and certainly nowhere near the numbers necessary to have an effect on any election." Or, to put it another way, about as many people say they've been abducted by space aliens as say they've committed voter fraud.

The second justification for voter ID laws is that they aren't motivated by discriminatory intent. But this new paper finds a solid link between legislator support for voter ID laws and bias toward Latino voters, as measured in their responses to constituent e-mails.

In short, voter ID laws are simply racially-motivated solutions to a problem that never existed.