As President Trump promises a major rollback of the post-financial-crisis rules on banks, his administration is muddying his deregulation message by pushing a new Glass-Steagall, a recession-era policy more commonly associated with Sens. Bernie Sanders and Elizabeth Warren than with Republicans.

The 1933 Glass-Steagall law, mostly repealed in the late 1990s, separated commercial and investment banks. Reinstating it would effectively break up megabanks with diverse lines of business, such as JPMorgan Chase, Citigroup and Goldman Sachs, the last of which notably has many alumni in the White House.