All the while, Stumpf has been hailed by other banking executives. The CEO of Germany’s embattled Deutsche Bank AG, John Cryan, once said he wished he instead could have "a relatively easy life" at the helm of Wells Fargo, making a good return on retail banking. Even Dimon couldn’t match Stumpf’s total return and pointed earlier this year to Wells Fargo as a competitor he must most keep an eye on.

"He’s like Americana in the form of a large bank CEO," Mike Mayo, a bank analyst at CLSA Ltd., said of Stumpf in an interview Tuesday. "He’s the preeminent retail banker."

Cross-Selling

Wells Fargo’s strategy included a heavy emphasis on cross-selling products -- a consumer opening a checking account was pushed to take a credit card, for example.

But it was that technique that landed the bank in trouble, according to the U.S. Consumer Financial Protection Bureau, which investigated the wrongdoing along with the Office of the Comptroller of the Currency. Employees “secretly opened unauthorized accounts to hit sales targets and receive bonuses,” CFPB Director Richard Cordray said in a statement.

Wells Fargo, which said it fired 5,300 employees over five years for the practices, also plans to eliminate product sales goals and instructed U.S. call center workers to temporarily halt cross-selling of financial products.

“The regulators’ findings are consequential for a bank such as Wells Fargo, which historically has had strong customer satisfaction scores and a reputation for sound risk management,” Moody’s Investors Service wrote in a report Monday. “We do expect some immediate damage to Wells Fargo’s reputation from this embarrassing episode.”

Stumpf E-Mail

In an e-mail to Wells Fargo customers Wednesday, Stumpf said the bank is always trying to do the right thing. “In this instance we did not -- and that is simply not acceptable,” Stumpf wrote. “Last week’s news did not reflect Wells Fargo at its best.”

Ed Mills, an analyst at FBR Capital Markets, said the Senate hearing has the potential to inflict further damage on Wells Fargo’s brand and that he wouldn’t be surprised if the U.S. Justice Department launches an investigation.