A major test is in Wisconsin, where citizens are set to cast their ballots in Tuesday’s Republican and Democratic presidential primaries. For the first time, its 4.5 million voting-age citizens will face strict new photo identification requirements that, according to critics, could limit or even nullify the ability to cast a vote. Making the issue of enfranchisement more fraught, there had been a lack of state funds for a public service announcement campaign meant to educate voters about the new requirement.

Five years ago, Wisconsin lawmakers invoked worries about fraudulent voting to justify passing legislation that requires citizens to show official identification before they can enter the polling booth. Since then, the law has been tied up in years of legal challenges—reaching as far as the U.S. Supreme Court—which has delayed its implementation until now.

Once known as a bastion of progressive government, Wisconsin was among several states that cracked down on poll access after the 2008 election, where an unexpected surge in turnout among African-Americans and young voters undercut the white, middle-class core voting demographic.

Well over half the states weighed adding more voter restrictions, inspiring criticism that—in the absence of provable cases of widespread fraud—states were simply trying to reshape the voting pool.

Such efforts have been criticized by civil liberties groups as being modern-day equivalents of the poll taxes and literacy tests that in the past singled out poor, mostly African-American citizens, particularly in southern states. In the era of the country’s founding fathers, the right to vote was restricted to white, property-owning men. Since then, ensuring that voting became and remained a basic constitutional right has been hailed as one of the country’s signature accomplishments.

For many years, a number of states have required voters to present some kind of identification, but the required documents have often been as basic as a current utility bill or a bank statement. Sometimes people showed a driver’s license. But it was not until 10 years ago that Indiana became the first state to require government-issued photo identification—a law that was upheld by the U.S. Supreme Court in 2008.

That judicial seal of approval opened the floodgates for other states to erect new voting parameters. Wisconsin and seven other states—Indiana, Georgia, Kansas, Mississippi, North Dakota, Tennessee, Virginia, and Texas—adopted the most stringent curbs.

Wisconsin’s measure, signed into law by Republican governor Scott Walker in 2011, requires voters to show valid photo identification before they can cast a ballot. The identification must be a current or recently expired Wisconsin driver’s license; a U.S. passport; a photo identification issued by the military, Indian tribe, or certain state colleges; or a recent certificate of naturalization.

While the majority of citizens have a form of identification, many on the lower-income rungs—especially those who do not drive—cannot easily obtain such credentials. The Brennan Center for Justice at New York University, which studies voting rights, has estimated that some 11% of the country’s voting age citizens do not have qualifying photo identification.

How that will reshape the current primary election campaign is hard to gauge.

Despite the talk of voter fraud, there have been few prosecutions of it. But allowing relatively unfettered voting has had undeniable effects, especially in 2008 when minority and youth voters flocked to the voting booth in unexpected numbers. This helped Barack Obama win North Carolina’s cache of electoral votes and become the first Democrat to carry the state in more than three decades.

In 2013, North Carolina’s legislature passed new voter identification regulations. Today they are being fought in federal court, and the presiding federal judge declined to block them during the recent March 25 presidential primaries. In order to cast a ballot, voters had to show one of six types of identification or file a provisional ballot, which requires a level voter follow-up that decreases the likelihood that such votes will be counted as valid.

The larger question is whether voting identification requirements will discourage young, poor and marginalized citizens from voting. Wisconsin will serve as a representative petri dish in this regard. The state’s statistics, according to the U.S. Census Bureau, roughly mirror the country. In Wisconsin, slightly more than 86% of its eligible voters are white, and 11% are either African-American or Hispanic. Wisconsin’s poverty rate is a little over 11%, household income around $53,000, and one-third of voting-age residents have a college degree, all on par with the rest of the country.

During the 2012 trial challenging the law, experts disagreed over the number of voters who would be affected by Wisconsin’s stringent requirements, in part because there is so little past data to go on. How much the new laws will curb or reshape voter turnout is unknown, Richard L. Hasen, a professor at University of California’s Irvine School of Law, recently told Pacific Standard.

“But there’s no question that in a very close election, they could be enough to make a difference in the outcome,” said Hansen, who has written several election-related books, including, The Voting Wars: From Florida 2000 to the Next Election Meltdown.

Wisconsin voters will soon get an opportunity to see how voting limits shape the state’s primary outcomes. And many more voters will be confronted with the same issue as soon as November’s general election. The turnouts will be higher and the stakes greater—and the limits perhaps more measurable—in key states like Texas.