A home will not become a home if you have to fight your way past predatory lenders and a two-tiered banking system to get one. That may be the plight of many African American bank customers in New York who want to achieve the American dream of home ownership, at least according to the state’s attorney general, Eliot Spitzer, who has launched a mortgage lending investigation after analyzing lending data obtained under the federal Home Mortgage Disclosure Act.

As explained in a court filing this week, the Spitzer inquiry discovered “substantial racial disparities in interest rates charged by various banks on their New York State loans.” The data, according to the attorney general’s office, “revealed that at Wells Fargo, African American customers were 3 times more likely to receive high cost loans; at JP Morgan Chase and Citigroup, African American customers were nearly two times more likely to receive high cost loans, and at HSBC … African American customers were about 1.5 times as likely to receive such loans.” Under New York state’s anti-discrimination laws, Spitzer’s office said, that data establishes a prima facie case of race-based discrimination in credit offerings.

“But wait, that’s New York state, and Spitzer is a Democrat running hard for governor,” you may be thinking. “What does any of this have to do with Washington?” Well, plenty.

It so happens that Washington believes New York has no business sticking its nose into the business of national banks doing business in the Empire State. That view, expressed by the federal Office of the Comptroller of the Currency, also applies to the Union’s 49 other states.

The OCC says it reached out to Spitzer last month to see how they each could work in a complementary way to uphold anti-discrimination lending laws, but he wouldn’t play ball. The federal agency feels so strongly about keeping New York away from single-handedly investigating racial disparities in home mortgage lending by the big banks that it went to federal court with the representatives of the big banks last week and asked that Spitzer be stopped in his tracks with a temporary restraining order. The Office of the Comptroller of the Currency claimed that the New Yorker’s probe “creates confusion and uncertainty” and undermines the OCC’s ability to do its job. But Judge Sidney Stein of the U.S. District Court in Manhattan refused to block Spitzer’s review.

Folks living beyond the Hudson River may be wondering what’s going on. Is this a federal-state turf battle or, as Spitzer charges, an example of the banks enjoying “the cozy embrace of their would-be national regulator?”

For the record, I worked nearly 10 years for a national bank, so I’m familiar with the OCC’s supervisory responsibilities for the national banking system. And until last year my wife was a director of a West Coast mortgage lending institution. I know that some lending disparities are based on more than race and that they can be explained. Apparently so does Spitzer, who has asked the banks to provide, on a voluntary basis, their explanatory data for scrutiny by his office.

Spitzer’s position is straightforward: A national bank engaging in discriminatory loan pricing in violation of state anti-discrimination laws shouldn’t be shielded by the federal government. What’s more, he suggests that the Office of the Comptroller of the Currency is hardly a ball of fire when it comes to anti-discrimination enforcement. It has no history of pursuing civil rights enforcement in New York, according to Spitzer’s press secretary, Juanita Scarlett. Contrast the OCC’s record with that of Spitzer, who since 1999, Scarlett said, has settled about a dozen cases against major financial institutions for engaging in predatory lending practices targeting minorities, the elderly and poor people.

So what to do? It’s simply not enough for Washington to charge that Spitzer is politicizing the lending discrimination issue because of his race for the statehouse in Albany. The Office of the Comptroller of the Currency, in the face of the HMDA loan pricing data, has a duty to review the material and act where required.

But is that now the case?

Is the OCC’s approach to banks today closer to that of a trade industry leader than that of a federal regulator? In a speech last fall before the Consumer Bankers Association, acting comptroller of the currency Julie Williams warned her audience that the Home Mortgage Disclosure Act required bankers to publicly report new and more detailed data concerning their home mortgage lending business. Higher-priced loans for the first time had to be reported by race, ethnicity, income level, and gender, and the racial and ethnic composition and income level of the census tract in which the property is located. The thrust of her message to the bankers: “Be prepared.”

A failure of preparedness, Williams warned, could be costly, not only for individual banks but for the entire industry. She observed that “a failure to adequately address a compliance risk issue can create reputation risk implosion that can wound an institution’s business prospects, torpedo its stock price and in some cases prove mortal to its ability to continue an existing franchise.”

And of course she’s right. The banking industry’s reputation is at stake. But what, pray tell, about those people for whom home ownership is placed out of reach because of a bank’s unfair lending practices? Is Washington as riled up about that? Which may help explain why Eliot Spitzer is challenging the Office of the Comptroller of the Currency and intervening, on behalf of consumers, with lenders – even in court if necessary. Would that Washington cared as much.

Mr. King is a columnist and deputy editorial-page editor at the Washington Post.