WASHINGTON -- The housing and financial crisis convulsing the U.S. is powering a new wave of government regulation of business and the economy.

Federal and state governments alike are increasingly hands-on in their effort to deal with failing businesses, plunging house prices, worthless mortgages and soaring energy prices. The steps add up to a major challenge to the movement toward deregulation that has defined American governance for much of the past quarter-century since the "Reagan Revolution" of the early 1980s. In fact,...