Affirmative action in college admissions has survived yet another Supreme Court challenge. The Court ruled 4-3 on Thursday that the University of Texas Austin's admissions procedures are constitutional, deciding Fisher v. Texas for the second time in three years, this time in the university's favor.

Justice Anthony Kennedy, writing for a four-justice majority that also included Ruth Bader Ginsburg, Sonia Sotomayor, and Stephen Breyer, concluded that the university's consideration of students' race was constitutional. (Here is the full opinion. Justice Elena Kagan recused herself because she did work related to the case during her time as solicitor general.)

UT Austin had specific goals for the diversity of its student body, and the majority was convinced by the university's argument that they could not achieve those goals in any other way.

UT Austin's admission plan is somewhat unique. Kennedy cautioned that the university should continue to reevaluate the plan as more evidence emerges about its effects. And so the opinion itself doesn't make sweeping proclamations about how long affirmative action will be necessary, as former Justice Sandra Day O'Connor did with Grutter v. Bollinger in 2003.

Still, when the Court voted to take up the Fisher case for the second time in three years, many speculated that this would be the opinion that gutted the use of race in college admissions. Instead, the case was an outright win for the University of Texas and the Court's liberals, although it reiterated to colleges that their affirmative action plans will have to meet high standards if challenged in court.

Why Abigail Fisher sued over the University of Texas's admissions policy

The case, Fisher v. Texas, challenged UT Austin's admissions procedures. Most of its students are chosen by admitting the students at the top of every high school class in the state.

Because Texas's high schools are generally racially homogeneous, that ensures a certain amount of racial diversity: The majority-black high schools send black students, the majority-Latino high schools send Latino students, and the majority-white high schools send white students.

But the university also admits some students who aren't in the top 10 percent of their high school class through another process, one that takes into account musical and athletic talent, as well as race and other factors. That's the process that was challenged by Abigail Fisher, who was denied admission through the so-called "holistic review."

Fisher has since graduated from Louisiana State University. But her challenge to the University of Texas admissions policy lasted longer than her college career.

At the heart of the case is whether the top 10 percent plan creates a diverse student body without the need for considering individual students' race in the admissions process. The Supreme Court has ruled that the educational benefits of diversity for all students should be the rationale for affirmative action, rather than giving black and Hispanic students a leg up because they've historically been discriminated against.

The case first reached the Supreme Court in the 2012-'13 term, but the Court sent the case back to the Fifth Circuit, arguing that it didn't hold the university to a high enough standard in determining whether its use of affirmative action was constitutional.

A panel of three judges from the Fifth Circuit, in July 2014, reviewed the case using that higher standard and again found in the university's favor. And the opinion essentially called the Supreme Court's bluff, arguing that if the Court wanted a different result, it would have to overturn Grutter v. Bollinger, the 2003 case that found affirmative action was constitutional if used as part of a holistic review of an applicant's credentials.

The big question was about how to define "diversity"

The 10 percent plan does create some racial diversity at the University of Texas, where only 4 percent of students are black. In 2014, three-quarters of them were admitted on the basis of their high school rank.

But schools serving a student body that consists mostly of students of color are more likely to be poor, and they're more likely to offer an inferior education, as measured by students' test scores, than the predominantly white schools that the university's white students come from.

The university argued that the top 10 percent plan wasn't sufficient because it didn't achieve true diversity. The students of color admitted under that plan were often from poor families and attended high schools that didn't offer an education that could prepare them as well for college. They often had lower test scores on the SAT and ACT.

The result, the university argued, was that although the entering class might be racially diverse, it wasn't diverse in the fullest sense. It didn't include students of color from middle-class families or from better high schools, or students of all races with talents not captured in their class rank.

Fisher's lawyers argued that the university was stereotyping the black and Hispanic students admitted through the top 10 percent plan by undercutting their potential. But the Supreme Court didn't buy that argument. Nor did Kennedy find the argument that the top 10 percent plan alone would have created sufficient diversity.

"A system that selected every student through class rank alone would exclude the star athlete or musician whose grades suffered because of daily practices and training," he wrote. "It would exclude a talented young biologist who struggled to maintain above-average grades in humanities classes. And it would exclude a student whose freshman-year grades were poor because of a family crisis but who got herself back on track in her last three years of school."

The opinion was narrow, but it shows the hurdles affirmative action programs will have to clear

When the Supreme Court last decided Fisher v. Texas in 2013, sending the case back to the Fifth Circuit, it set high standards for affirmative action programs to meet:

Colleges could only consider race in admissions if they can give a "reasoned, principled explanation" for wanting a diverse student body.

The programs must be narrowly tailored, or specifically designed to accomplish a goal.

And they must withstand strict scrutiny, meaning colleges have to prove affirmative action was the only way to accomplish its diversity goals.

In the majority opinion, Kennedy concluded that the university's plan met those standards: " The University spent seven years attempting to achieve its compelling interest using race-neutral holistic review. None of these efforts succeeded."

But those three requirements are still a higher bar to judicial approval than affirmative action faced before Fisher was decided for the first time. And because the top 10 percent plan is unique, the decision does not provide much guidance on how other universities can ensure their admissions procedures are constitutional.

The opinion ends with a note of caution: The University of Texas got a win, but it wasn't being written a blank check. "It is the University's ongoing obligation to engage in constant deliberation and continued reflection," Kennedy wrote.

The Court's conservatives dissented strongly

The three justices who dissented — Chief Justice John Roberts, Justice Samuel Alito, and Justice Clarence Thomas — argued that the University of Texas's plan failed to meet the Supreme Court's requirements, and that the university's justifications for why it needed to consider race in admissions were amorphous and frequently shifted.

In the dissent, Alito argued that the university was defining diversity only in terms of numbers, and that the real goal was "racial balancing" — or getting the demographics of the university to reflect the demographics of the state. The Court has held that racial balancing is unconstitutional.

To make that point, Alito argued at length that the University of Texas is disadvantaging Asian-American students, who are overrepresented in classrooms relative to their share of the state's population but make up a very small slice of the student body overall.

"In UT's view, apparently, 'Asian Americans are not worth as much as Hispanics in promoting ‘cross-racial understanding,' breaking down ‘racial stereotypes,' and enabling students to ‘better understand persons of different races,'" Alito wrote.

He argued on behalf of the minority that the University of Texas did not do enough to prove its case: "Even though UT has never provided any coherent explanation for its asserted need to discriminate on the basis of race, and even though UT's position relies on a series of unsupported and noxious racial assumptions, the majority concludes that UT has met its heavy burden. This conclusion is remarkable — and remarkably wrong," the dissent concluded.