A trial that could have implications for voter turnout in Iowa began Monday, with challengers arguing that a new law burdens voters disproportionately and the state defending it as a way to prevent fraud and human error.

House File 516, passed in 2017, requires pre-registered voters to present government-issued identification at the polls on Election Day, among other disputed provisions.

The law was intended to “modernize election procedures and, with respect to voter verification, ensure the integrity of and instill public confidence in all elections in this state," Matthew Gannon, an assistant attorney general, said during opening statements Monday before Polk County District Judge Joseph Seidlin, who will decide the case.

"This comprehensive and innovative approach will eliminate the potential for human error and fraud, and secure Iowa’s elections moving forward," Secretary of State Paul Pate said in 2017, after the bill passed. "It should be easy to vote, but hard to cheat. This bill accomplishes both of those goals."

The League of United Latin American Citizens of Iowa and an Iowa State University student sued to overturn the law, which they say violates the sections of the Iowa Constitution that protect the right to vote, due process, equal protection and freedom of speech.

Their lawsuit, filed in May of 2018, claims the new law will make voting "more complicated, cumbersome and time-consuming without adequate justification for doing so."

Bruce Spiva, an attorney representing the plaintiffs, said during opening statements that the law "erects significant barriers," particularly for voters who are young, elderly, poor, lacking education, minorities, women and Democrats.

"There is no crisis that required this measure," Spiva said, contending that voter fraud was already virtually nonexistent in Iowa. "The state should not put unnecessary hurdles in front of the ballot box."

The burdens imposed by the law, including a "dizzying array of rules," far outweigh any benefits of the law, he added.

► More:Iowa House approves voter ID bill following 12 hours of debate

Gannon defended the law, saying that the secretary of state's office and the Iowa Department of Transportation took on an "unprecedented" project in which they created a database to identify Iowa voters without driver's licenses or an Iowa nonoperator's identification, and sent them a voter ID card for free beginning in December 2017.

“No other state in the country went to such lengths when enacting a voter ID statute," Gannon said.

He also addressed a section of the law authorizing county election officials to reject absentee ballots if they decide the voter's signature is invalid.

The plaintiffs argue this could disenfranchise some Iowans. Gannon said auditors aren't required to evaluate every signature.

“The challenged provisions of HF 516 do not unconstitutionally burden the right to vote of Iowa voters because they apply to all voters in a uniform and non-discriminatory way and are properly tailored to advance the legitimate state interests," Gannon said in response to the lawsuit's claim that certain demographics of voters are disproportionately affected.

In July of 2018, Polk County District Court Judge Karen Romano granted a temporary injunction, blocking several of the law's restrictions on absentee voting. The Iowa Supreme Court later affirmed much of the injunction, which will last until the case is resolved.

Among those set to testify in the 10-day-long trial at the Polk County Courthouse: county auditors, Iowa voters, political science professors, a former director of elections for the state, LULAC representatives and the Iowa State University student who is a plaintiff.

Taylor Blair, a rising senior at Iowa State University, testified Monday that he spends about as much time working with College Democrats of America as he does on homework, often helping to register voters on and off campus. He's also worked for numerous campaigns, including Hillary Clinton's presidential campaign, a congressional race and a local city council race.

When Blair began working with voter engagement in 2016, the conversation surrounding voter registration was much simpler, he said.

Now, Blair said, he spends a lot of time helping student voters learn to jump through hoops as a result of the new law.

"I'd rather talk to them about what matters," he said.

More:Iowa voter with no ID mistakenly turned away from the polls in special election

Blair, who doesn't have an Iowa driver's license, was eligible in December 2017 for a state-issued voter ID card. But, he said, his name was mixed up with a woman who had the same name and birthday as his own, so he didn't receive his card. Instead, he had to reach out to his county auditor to ask what happened to his ID.

Most students wouldn't take the extra steps to do that, he said:

“As soon as they face any sort of push-back at the polling place, they back off, they go back to their dorm, and I think it’s a shame.”

Register reporter Stephen Gruber-Miller contributed to this story.

Anna Spoerre is a breaking news reporter at the Des Moines Register. She can be reached by email at aspoerre@dmreg.com, by phone at 515-284-8387 or on Twitter at @annaspoerre. Follow the Register on Facebook and Twitter for more news.