"In light of the longstanding judicial interpretation of the FHA to encompass disparate-impact claims and congressional reaffirmation of that result, residents and policymakers have come to rely on the availability of disparate-impact claims," Justice Kennedy wrote in the court's opinion.

When the Supreme Court agreed to hear a Texas "disparate impact" case last year, banks hoped it would end the use of the divisive legal theory used by regulators and other authorities. But the court's Thursday decision, by contrast, appears to strengthen the government's hand.

The court's decision upholding disparate impact — which makes defendants liable in fair-housing and fair-lending cases even if discrimination was unintentional — bolsters efforts by the Consumer Financial Protection Bureau and other agencies as well as consumer advocates to bring claims while dampening other challenges to the theory, observers said.

"It will embolden activist groups, private plaintiffs and the government — in particular the CFPB, the Department of Justice's civil rights division, prudential banking regulators and [the Department of Housing and Urban Development] — to continue to advance in both examinations and investigations inquiries into policies and practices that are predicated on disparate impact analysis," said Benjamin Saul, a partner at Goodwin Procter LLP.

Yet at the same time, banking industry representatives did see positives in the ruling, which was supported by five of the court's nine justices. The decision in the Texas Department of Housing and Community Affairs v. the Inclusive Communities Project appeared to set clear hurdles for plaintiffs to prove disparate impact claims, give defendants the ability to seek dismissal of cases early on and limit the damages for clear violations.

"It suggests that" a fair-lending violation "shouldn't warrant penalties. It should focus on correcting practices that caused the disparities," said Paul Hancock, a partner at K&L Gates.

Still, the ruling further cemented the use of "disparate impact." Experts said activists and regulators will likely continue to cite it in cases not just dealing with housing claims. The CFPB, for example, has used "disparate impact" in alleging discriminatory effects on car loan borrowers as well.

"I wouldn't want to be someone who is in the auto lending industry who disparately impacts people of color and expect that I would be protected down the line," said John Taylor, the chief executive of the National Community Reinvestment Coalition. "The court affirmed what people who understood the context of disparate impact already knew. One may not be able to show direct discrimination in auto lending or housing. But if you can show that, because of decisions made by the company, the policy had the same impact as if you were doing direct discrimination, that's no longer a safe harbor."

The case involved affordable housing tax credits distributed by the state of Texas. The Inclusive Communities Project — a housing advocacy group — sued over claims that the state's distribution method led to affordable housing options being overly concentrated in minority areas.

The court concluded in the case that "disparate impact" is recognized — or "cognizable" — under the Fair Housing Act, meaning plaintiffs can allege discrimination in housing-related decisions that negatively affect minority areas even if no discriminatory treatment was intended.

"In light of the longstanding judicial interpretation of the FHA to encompass disparate-impact claims and congressional reaffirmation of that result, residents and policymakers have come to rely on the availability of disparate-impact claims," Justice Anthony Kennedy, who ruled along with the court's four progressive justices, wrote in the court's opinion. He noted that "many of our Nation's largest cities — entities that are potential defendants in disparate-impact suits — have submitted an amicus brief in this case supporting disparate-impact liability under the FHA."

The decision is a huge setback to lenders and industry advocates who say disparate impact unfairly victimizes financial institutions that are not aware that their credit policies may have a disproportionate effect on minority neighborhoods.

The American Bankers Association "and our members are strong advocates for fair lending and enforcement of the Fair Housing Act. Disparate Impact theory, however, is not the right tool to achieve fairness and prevent discrimination in lending," Frank Keating, the ABA's president and chief executive, said in a statement. "This approach can have unintended consequences, such as causing financial institutions to shrink their operations rather than risk litigation, hurting the very groups it is intended to help."

But consumer groups, regulators, civil rights attorneys and Democratic lawmakers all applauded the decision.

"The court's ruling preserves one of the most important tools we have to fight discrimination and ensure that all Americans have fair access to housing and economic opportunity," Sen. Sherrod Brown, D-Ohio, the ranking member of the Senate Banking Committee, said in a statement. "We need to continue efforts to combat discriminatory practices, not just in housing but in all consumer financial markets."

Yet some observers said the immediate impact of the ruling may be limited, since banks had assumed "disparate impact" to be the law of the land unless overturned by the courts.

"The industry has been operating form a presumption that it's susceptible to disparate impact risk over the years," Saul said. "Most industry players have put in place a compliance regime meant to mitigate inherent disparate impact fair lending risk. Those efforts will continue and probably intensify now that it's very clear that disparate impact claims are cognizable under the FHA."

Subscribe Now

Access to a full range of industry content, analysis and expert commentary.

30-Day Free Trial

No credit card required. Access coverage of the securitization marketplace, including breaking news updated throughout the day.