A lot of people misunderstand the issues in Ricci v. Destefano. This is because you have to know quite a bit about both federal law and constitutional law to understand it. Most do not. Thus, massive confusion.
To analyze Ricci, keep a few things in mind.
1. You can't give a test that disparately impacts a protected class. Griggs v. Duke Power Co. A racial group (majority or minority) is a protected class. Title VII of the Civil Rights Act of 1964.
Think of disparate impact as one of two things: unintentional discrimination; or discrimination you can't prove.
Disparate-impact-as-unintentional-discrimination: Let's say you give a test that you think people should pass. It's not your goal to make a member of a protected class flunk it. It just so happens that a lot of members of a protected class flunked the test. Thus, your test has a disparate impact on a protection class. It is therefore illegal under Title VII.
Disparate-impact-as-hiding-the-smoking-gun: Let's say you hate black people. You know that most black people in your community do not have high school diplomas. To avoid hiring black people, you require all job applicants to have a high school diploma. Well, you do intend to discriminate. But we can't prove it because you've hidden your discriminatory intent. Thus, to prevent people like you from gaming the system: You can't require a high school diploma unless you can show that it's really required for the job. (This is known as the bona fide occupational qualification - bfoq - exception.)
Either way, an employment requirement that has a disparate impact is not allow under Title VII (subject to the bfoq exception).
2. You cannot purposefully discriminate against a protected class. A racial group (majority or minority) is a protected class.
The test in Ricci disparately impacted a protected class: No blacks passted the test. A lot of whites, however, did pass the test.
The city wanted to throw out the test results because too many whites and not enough blacks passed the test.
Not hiring the whites was purposeful discrimination. The whites were not hired because of their race. Had, say, 50% of the people who passed the test had been black, the test results would have been certified. (Or, at least, that is what the allegations - which must be accepted as true - state.)
So there is purposeful racial discrimination against whites. The test also has a disparate impact on blacks.
Quite the paradox, 'eh?
Many say, Yes. That is because they do not understand the con law of the case.
HOWEVER, unintentional discrimination is prohibited under Title VII - a federal statute. Purposeful discrimination is prohibited under the Equal Protection Clause - the United States Constitution. Disparate impact is not a violation of the Equal Protection Clause. Washington v. Davis.
The Constitution says you can't do one thing, namely, discriminate against whites. (You can't purposefully discriminate against blacks, either.) A federal statute says you cannot do something else, namely, give a test that disparately impacts blacks.
The Constitution trumps federal statute. After all, federal statutes exist only as an extension of the Constitution, at least if the Supremacy Clause is taken seriously.
Oh, but can't Congress say that it needs to protect blacks through use of a disparate impact theory? Nope. City of Boerne v. Flores. The Courts, not Congress, get to decide what rights are protected under the Constitution. Since the Courts, in Washington v. Davis, said that disparate impact was not viable under the Equal Protection clause; well, it's not.
Thus, Ricci is an easy case. The test results must be certified.
Of course, in my post I cite cases. The Court has the power to make me cite new cases. Ricci v. Destefano might stand for some new legal proposition. Ruling against the plaintiffs in Ricci, though, would require the Court to change existing law.