But research, particularly of voter ID laws in Texas, Wisconsin and other states, provides an imprecise picture of how much similar laws suppress turnout. And Eitan Hersh, a Tufts University political scientist who contributed to the analysis of Texas’ strict voter ID law, said research indicated that voter ID laws could alter very close elections but might not be as influential as some critics claim.
“These laws are complicated to assess,” Mr. Hersh said. “Alabama was a place where there was a lot of campaigning, and when campaigns liven up, you have a lot of mobilization efforts” that could offset the effect of an ID law on turnout…..
Some voting rights advocates stress that the relevant measure should be whether people were unable to vote, not whether particular policies determined the outcome of the election.
“Voter suppression might not be attributable in every instance to changing an election outcome, but it’s significant to people who have barriers in front of them at the ballot box,” said Myrna Pérez, the deputy director of the democracy program at the Brennan Center for Justice at the New York University School of Law. She added: “The country is going to be poorer if we only care about voter suppression when it affects the outcome.”
The outcome, however, is increasingly the standard by which voting-rights cases are decided. The Supreme Court’s Shelby County v. Holder decision, which dramatically scaled back the Voting Rights Act, relieved scores of states and local governments with a history of bias from the need to prove that new election rules did not discriminate. Since 2013, the burden of proving discrimination — and the cost of detecting and litigating it — has been shifted to minority voters and the groups that represent them.
To many, that’s a standard that rankles.