We do not think there's any documentation of the sort that you requested. A search in Lexis-Nexis turned up the most recent Capitol Hill hearing testimony from Julie L. Williams of the Office of the Comptroller of the Currency, as presented to the House Financial Services Committee on January 28, 2004.

Some relevant passages:

"Although some aspects of state anti-predatory lending laws - such as state restrictions on particular loan terms and state prohibitions on particular loan products - are preempted by the rule, the rule does not preempt anti-discrimination and fair lending laws. There appears to have been some misunderstanding on this point, perhaps because some state predatory lending laws have "fair lending" in their titles but do not actually address unlawful discrimination in lending.1

"The preemption rule, consistent with Federal judicial precedents,2 the extensive body of Federal anti-discrimination laws, and the OCC's unyielding commitment to national banks' fair treatment of their customers, does not preempt any law prohibiting discrimination in lending."

[...]

"Our existing regulations implemented the visitorial powers statute by providing that state officials are not authorized to inspect, examine, or regulate national banks, except where another Federal law authorizes them to do so.4 The amendment to the visitorial powers rule that we have just issued clarifies that the scope of the OCC's exclusive visitorial authority applies to the content and conduct of national bank activities authorized under Federal law. In other words, the OCC is exclusive supervisor of a national bank's banking activities. The rule state officials from enforcing state laws that do not pertain to a national bank's banking activities, such as health and safety standards or criminal laws of general applicability."

A further search of Lexis-Nexis did not find any further testimony that contradicted this most recent testimony defending the preemption of state banking regulations.

You may also be interested in reading a February 12, 2002, speech, "Comptroller Calls Preemption a Major Advantage of National Bank Charter," at www.occ.treas.gov/ftp/release/2002-10a.txt.

Some relevant passages:

"[T]he courts, echoing McCulloch v. Maryland, have been emphatic about where the states may not go. State laws may not "stand as an obstacle" to the accomplishment of the purposes for which Congress created the national bank charter.

"The states may not "prevent or significantly interfere with" the activities lawfully engaged in by national banks. They may not "impair" or "prevent" national banks from exercising congressionally granted powers. They may not regulate at all in areas in which the federal interest predominates or where Congress has "occupied the field" to the exclusion of the states.

"Decisions of the Supreme Court have overwhelmingly endorsed the preemption doctrine as it applies to national banks -- a record of consistency that transcends changes in the political or philosophical makeup of the Court."

[...]

"While the OCC has no self-executing power to preempt state law, it has on many occasions expressed opinions about the preemptive effect of federal law. In recent years, for example, we have opined that state laws that impose restrictions on such financial activities as ATM fees, auctions, and trust services cannot lawfully apply to national banks."

[...]

"It's important to note that, for better or worse, the preemption doctrine is value-blind and agnostic with respect to the desirability of the state law involved. In preemption situations, the only relevant issue is whether the state law would impair or significantly interfere with a national bank's exercise of powers granted to it under federal law. If such an impact is found to exist, federal law must prevail. Any opinions we might have about the desirability or merit of the laws in question are not relevant."

See also, from March 25, 2004, "First Senior Deputy Comptroller Julie L. Williams Sets the Record Straight Regarding Nature, Consequences of OCC's Recent Preemption Regulations" (www.occ.treas.gov/ftp/release/2004-25a.pdf) and other speeches at www.occ.treas.gov/speeches.htm.

So, it looks like lots of documentation from the OCC regarding their right to preemption of state regulations.

Below are some excerpts from congressional testimony by John Hawke on April 1 2004 re: the OCC preemptive power in issues of national banks complying with state laws.

HOUSE FINANCIAL SERVICES COMMITTEE
April 1, 2004 Thursday (Lexis Nexis)

"Preemption is a constitutional doctrine and whether we codified the preemption rulings in the regulation or not, these issues were going to come up in court. They have been coming up in court in wholesale numbers. We have had scores of litigations over the last decade involving issues of preemption. Our banks are faced with the uncertainty of litigation as they move into new products and new markets, and we have been asked on dozen of occasions to give interpretations about the applicability of state laws, and the reason we put out our regulation is to try to bring some predictability and clarity to long-standing doctrines."
...

We saw that in some cases these anti-predatory lending laws were impacting on the ability of our banks to provide good subprime credit in these markets. The secondary market was constricting and banks were moving out of markets. As I mentioned earlier, we were facing a high volume of litigation and inquiries about these preemption issues, and we felt that our banks needed guidance and that we needed to move ahead with that guidance.

And, finally, we thought that it was important that the predatory lending standard that we announced in the regulation go into effect and that that be out there so that banks would have -- and I appreciate that people think we didn't go far enough with that -- but that predatory lending standard that's in the regulation is something that nobody else has done and no other state or federal regulators have done, and we believed it was important to get that out there and get that into effect. ...
(Responding to Rep. Scott Garrett R-NJ)

HAWKE: No, I don't agree, with great respect, Mrs. Waters, because these laws and the North Carolina law is one example of this that have had adverse unintended consequences that I think all members of Congress should be concerned about. They have resulted in and threatened further constriction of the availability of subprime credit -- good, non-predatory subprime credit.

The subprime credit markets have expanded in recent years. They've been one of the reasons that home ownership in the United States is now at a record high level. Credit markets have opened up to people particularly in minorities that have not had access to credit before because of the advances in the subprime credit market. And what's happened with some of these predatory lending laws is that they have constricted the availability of subprime credit. When the New Jersey law was about to go into effect last November there was a story in the American Banker that said that subprime lenders plan to reduce their involvement in the subprime markets in New Jersey by 70 percent because of the New Jersey anti-predatory lending laws. ...
(Hawke responding to Rep. Maxine Waters D-CA)

So again, nothing advocating state laws that protect consumers, much defening the preemptive authority of the OCC.