Imani Clark, Aurica Washington, Crystal Owens and Michelle Bessiake are students at Prairie View A&M and Texas Southern University, two historically black colleges in Texas. They do not have a driver’s license or own a car, and do not possess one of the five forms of government-issued identification required by Texas to vote.

They can no longer vote with their students IDs in Texas, where a handgun permit is a valid voter ID but a student ID is not.

The four students are among the plaintiffs challenging the constitutionality of Texas’s voter ID law in federal court in Corpus Christi this week. The trial before Judge Nelva Gonzales Ramos, an Obama appointee, is expected to last two to three weeks.

In August 2012, a three-judge district court in Washington found that the law discriminated against black and Hispanic voters under Section 5 of the Voting Rights Act. The court called it “the most stringent [voter ID law] in the country.”

But after the Supreme Court’s decision in Shelby County v. Holder freed states like Texas with a long history of voting discrimination from having to approve their voting changes with the federal government, Texas wasted no time in implementing the blocked law. “With today’s decision, the state’s voter ID law will take effect immediately,” Texas Attorney General Greg Abbott announced hours after the court’s ruling. Groups like the Justice Department, NAACP Legal Defense Fund and the Mexican American Legislative Caucus are now challenging the law under Section 2 of the VRA, which remains on the books.

During the first round of court proceedings, Texas admitted that between 600,000 to 800,000 registered voters in the state lacked a government-issued photo ID, with Hispanic voters between 46.5 percent to 120 percent more likely than whites to not have the new voter ID. Those without a voter ID needed to pay for additional documentation to confirm their identities, with the cheapest option being a birth certificate for $22. Attorney General Eric Holder called it a “poll tax.”

Getting a voter ID in Texas isn’t as easy as you’d think. There are no DMV offices in eighty-one of 254 counties in the state, with some voters needing to travel up to 250 miles to obtain a voter ID. Counties with a significant Hispanic population are less likely to have a DMV office, while Hispanic residents in such counties are twice as likely as whites to not have a voter ID. (Hispanics in Texas are also twice as likely as whites to not have a car). So far, Texas has issued only 279 new voter IDs, even though hundreds of thousands of registered voters lack one.

The court based its ruling on three important facts:

(1) a substantial subgroup of Texas voters, many of whom are African American or Hispanic, lack photo ID; (2) the burdens associated with obtaining ID will weigh most heavily on the poor; and (3) racial minorities in Texas are disproportionately likely to live in poverty.

“A law that forces poorer citizens to choose between their wages and their franchise unquestionably denies or abridges their right to vote,” wrote Judge David Tatel. “The same is true when a law imposes an implicit fee for the privilege of casting a ballot.”

Those burdened by the law include 92-year-old Ruby Barber of Waco, who has voted in every presidential election since 1944 but could not easily obtain a voter ID because she does not have a driver’s license, birth certificate or marriage license. “I’ve voted all my life, and not to be able to vote—it just breaks my heart,” she said.

During the first test of the law last November, many voters—including a state judge and both candidates for governor—had to sign an affidavit to vote because the names on their IDs did not match their names on the voter registration rolls. Ninety-year-old Speaker of the House Jim Wright was denied a voter ID before his assistant procured a certified copy of his birth certificate.

Texas passed the voter ID law as “emergency” legislation at the beginning of 2011. It’s unclear what emergency the Texas legislature was responding to—since 2004, there have been only four cases of voter impersonation in the state. (In 2010, Abbott led a controversial armed raid of the offices of a Houston voter registration group, but no charges were ever filed.)

This case has important national significance for a few reasons.

Number one: as mentioned earlier, Texas passed the strictest voter ID law in the country and has done little to ensure that every registered voter will be able to cast a ballot. If the law is approved, it will set a precedent for similarly strict measures to be adopted elsewhere.

Number two: Texas has a significant governor’s race between Abbott and State Senator Wendy Davis in 2014. It is also trending blue in the long term. Texas Republicans believe voter ID will reduce turnout among Democratic-aligned voters. The former political director of the Texas Republican Party argued in 2007 that a voter ID law would add 3 points to the GOP vote.

Number three: Texas is a perfect case study for whether the existing provisions of the VRA can protect voters from discrimination. Since the federal courts have already judged Texas’s law to be discriminatory, any subsequent decision approving the law would show the devastating impact of the Shelby decision. Thus far in 2014, the federal courts have blocked Wisconsin’s voter ID law but did not grant a preliminary injunction against North Carolina’s tough new voting restrictions.

Already, jurisdictions in Texas, like the city of Pasadena, have changed their voting rules to dilute black and Hispanic representation. “The Justice Department can no longer tell us what to do,” Pasadena Mayor Johnny Isbell said when the city passed a referendum last year eliminating two Hispanic city council seats.

Number four: the Justice Department and civil rights groups are arguing that Texas’s voter ID law was enacted with intentional discrimination and the state should have to approve its voting changes with the federal government for a period of time as a result. This little-used bail-in provision has been described by Travis Crum of Yale Law School as the “secret weapon” of the VRA. But it’s very difficult to prove intentional discrimination and only nine jurisdictions have been bailed-in to the VRA since 1975.

However, a federal court also found in 2012 that Texas’s redistricting maps were “enacted with discriminatory purpose.” Like voter ID, that case is now being tried again under Section 2. “The State of Texas has employed a variety of devices to restrict minority voters’ access to the franchise,” DOJ argues. “In the absence of relief…there is a danger that Texas will continue to violate the Voting Rights Act and the voting guarantees of the Fourteenth and Fifteenth Amendments in the future.”

Texas has lost more Section 5 lawsuits than any other state. If there’s any place in the country that needs to be monitored under the VRA, this is it.