While Mr. Lewis remains chief executive — the board expressed its unanimous support for him — many inside and outside the bank wonder if he can hang on. Mr. Lewis confronts daunting challenges, and many of his investors are losing patience. Even after receiving billions of taxpayer dollars, some analysts say, the bank may still need to raise more to shore up its weakened finances.

“Ken Lewis has now become the lightning rod of controversy, and that is highly distracting,” said Jeffrey A. Sonnenfeld, a professor at the Yale School of Management, who believes Mr. Lewis should resign. “Even if everything he did was appropriate, it has hampered his legitimacy to lead.”

It was not long ago that Mr. Lewis was celebrated for his vision. His daring takeover of Merrill Lynch was the latest in a series of high-profile acquisitions that helped transform Bank of America into a national powerhouse. His conquests included the Countrywide Financial Group, the giant mortgage lender which, for many, came to symbolize the excesses of the subprime era. In December, the American Banker, the daily chronicle of the banking industry, named him 2008 Banker of the Year.

Image Kenneth D. Lewis Credit... Matthew Cavanaugh/European Pressphoto Agency

But that was then. Now Mr. Lewis is drawing fire for overpaying for Merrill, whose gaping losses prompted Bank of America to seek a second rescue from Washington. The attorney general of New York is examining whether Mr. Lewis adequately disclosed the risks of the takeover to his shareholders, drawing headlines — and more ire. The timing could hardly be worse. Bank of America is bracing for another wave of loans to go bad as the recession drags on.