House investigators on Monday charged Rep. Maxine Waters with "improperly" exerting influence to help bail out a bank in which her husband held stock, handing more ammunition to Republicans eager to blast House Speaker Nancy Pelosi for overseeing a "House of scandal."

The House ethics panel said the office of the senior California Democrat violated conflict of interest rules by repeatedly lobbying the Treasury Department for bailout money on behalf of minority-owned OneUnited in which her husband held as much as $350,000 in stock. The bank received a $12 million slice of the taxpayer-funded Wall Street bailout.

Ms. Waters has fiercely proclaimed her innocence and asked the committee to make public the 10-page "statement of alleged violation" against her. Like Rep. Charles B. Rangel of New York, she has opted to let the matter play out in a public hearing before the bipartisan ethics committee, demanding that one be scheduled as soon as possible...