THE AMERICAN Civil Liberties Union went to court last month to challenge an egregious Kansas law that requires residents to provide proof of citizenship — such as a birth certificate — to register to vote. The requirement seems contrary to the intent of the federal Motor Voter law, which was supposed to make registration simple. But legal or not, this state law and others like it are truly awful public policy.

The case for the Kansas law is that noncitizens might be able to get driver’s licenses and register to vote at the department of motor vehicles, potentially allowing them to skirt the fraud prevention that more conventional voter-ID laws provide. But there is scant evidence of such voter fraud, and certainly not enough to justify demanding that people jump through even more hoops to cast a ballot.

When we asked Craig McCullah, a spokesman for Kansas Secretary of State Kris W. Kobach, for evidence that voting by noncitizens is a problem demanding a significant policy response, he responded, “If there is no murder in Washington, D.C., does that mean that Washington shouldn’t have a law against murder?”

Arizona State University’s News21 counted 2,068 cases of alleged voter fraud across the country between 2000 and 2012. Registration fraud accounted for about 18 percent of those cases — mainly occurring when paid registration workers signed up fake people in order to get more money. Maybe there is a tidal wave of undercover, malicious voter fraud occurring under the noses of hyper-zealous election officials. More likely, it simply is not a major problem. Kansas’s law might cut down on some rare instances of registration fraud, but that still would not justify the burdens it imposes on citizens trying to exercise a fundamental right.

The Kansas secretary of state’s office claims that there is no evidence that the state’s restrictions, which have been in place since 2013, have prevented anyone from voting. But evidence certainly exists that even conventional voter-ID laws, which erect lower barriers to the ballot box, discourage voting. A 2014 Government Accountability Office analysis found scattered instances of voter fraud in Kansas and Tennessee in the 2012 presidential election but a much more concerning two-to-three-percentage-point drop in turnout attributable to the states’ new voter-ID requirements. In the absence of strong evidence of a problem, the government should err on the side of encouraging the vote rather than turning it into a bureaucratic ordeal.

In other words, states should streamline the voter registration system, not complicate it. Oregon and California have moved to an automatic system, for example, registering people when they get driver’s licenses unless they specifically ask to opt out. This should be a first step toward universal voter registration. States, not individual voters, should take on the responsibility to keep voter rolls complete and accurate.