The courts have found that voter ID laws intentionally discriminate against voters of color. Now newly published research offers details about the laws' politically suppressive effects.

A study led by researchers at the University of California, San Diego (UCSD) that appeared last month in the Journal of Politics shows how strict voter ID laws drive down turnout of racial and ethnic minorities. A pre-publication version released last year drew much attention as it was the first to indicate that the proliferation of voter ID laws following the Supreme Court's gutting of the Voting Rights Act in its 2013 Shelby County v. Holder decision has indeed driven down minority turnout.

"When these laws are enacted, the voices of Latinos, Blacks, and Asian Americans all become more muted and the relative influence of white America grows," co-author Zoltan Hajnal told Facing South.

To date, few studies have documented the consequences of strict voter ID laws, which require voters to show one of a restricted number of IDs before casting a ballot. The study by Hajnal et al. looked at all 10 states that had a strict voter ID laws in place in 2014: Arizona, Georgia, Indiana, Kansas, Mississippi, North Dakota, Ohio, Tennessee, Texas and Virginia. Since then, the Texas law has been struck down by the courts while Wisconsin has adopted one.

Much of the previous research on voter ID effects analyzed elections that occurred prior to implementation of strict voter ID. It also relied on self-reported voter turnout, which is often overstated.

But Hajnal and his co-authors — Nazita Lajevardi of UCSD and Lindsay Nielson of Bucknell University — used data from the Cooperative Congressional Election Study to analyze the validated participation of racial and ethnic minorities during recent elections. They then compared voter turnout in states with strict ID laws to states without such laws.

Like most previous studies on voter ID, theirs found no significant difference in overall turnout when comparing strict and non-strict ID states. However, when they refined their research to specifically examine turnout by people of color, they saw a dip in their participation in states with strict ID laws.

Among the findings:

In states with strict ID laws, Hispanic turnout was 7.1 percentage points lower in general elections and 5.3 percentage points lower in primary elections compared to states without such laws.

There was no significant difference between turnout of African Americans in strict voter ID states and their counterparts in non-strict states in general elections. But in primaries, African American turnout was 4.6 percentage points lower in states with strict lD laws.

Turnout among Asian American voters in strict ID states was 5.4 percentage points lower in general elections and 6.7 percentage points lower in primaries.

White turnout increased slightly in strict ID states — 0.2 points in general elections and 0.4 points in primary elections.

Given the South's long history of racially discriminatory voter disenfranchisement, the researchers compared the effect of strict voter ID laws in Southern and non-Southern states. They found that the political consequences of voter ID laws were more pronounced in the South, skewing turnout toward the political right in both general elections and primaries.

"Since more states in the South have instituted strict voter identification laws than in any other region, the effects of these laws are being felt more in the South than elsewhere," Hajnal said.

The researchers offer two possible explanations for the effects of strict voter ID laws. Most obviously, some people simply lack the required ID. For example, Blacks, Latinos, and the poor are more likely to lack transportation to ID-issuing offices that are often miles away, particularly in rural areas of the South.

But the authors also consider that voter ID laws might discourage voting in more subtle ways.

"Where and when these laws are passed, members of certain groups might feel unwelcome at the polls," they write, pointing to previous research. "This is especially true for racial minorities, who have been the subject of election-related violence at different points in American history, but it could also affect those on the political left and potentially even younger socioeconomically disadvantaged."