The new bureau concentrates consumer protection in one agency, with the sole purpose of shielding Americans, and the financial system, from abusive and deceptive lending in mortgages, credit cards and other borrowing.

The banks — big campaign contributors — don’t want robust consumer protection because complex and obscure products are lucrative. House Republicans have begun to pass bills that would severely constrain the bureau’s power to write and enforce rules and reduce and imperil its budget. Mr. Obama has pledged to veto the bills if they reach his desk, but that won’t stop the assaults. Under the law, the bureau cannot exercise its full regulatory powers without a director. In May, 44 Republican senators vowed to block any nominee unless Democrats agreed to weaken the agency as called for in the House bills.

Last week, when President Obama nominated Richard Cordray, the former attorney general of Ohio and currently chief of enforcement at the bureau, Senator Richard Shelby of Alabama, the top Republican on the banking committee, wrote in The Wall Street Journal that the nomination was “dead on arrival.” Acting as if Dodd-Frank is not already the law of the land, he called on President Obama to “come to the negotiating table.”

Mr. Obama erred in passing over Elizabeth Warren — the Harvard law professor and consumer advocate who set up the bureau — for the director’s job. Mr. Cordray is a good choice, with a notable pro-consumer track record. Ms. Warren, who pioneered the idea for the bureau and helped push it through Congress, has drawn particular fire from banks and Republicans, who had turned their opposition to consumer protection into opposition to her.

In deciding not to fight for Ms. Warren, the president has forfeited the opportunity to stand up to the banks and to highlight their relentless efforts to undermine reform. It is hard not to think that Mr. Obama was worried that choosing Ms. Warren would have cost him and Democratic senators campaign contributions from the banks.