President Obama is now, finally, getting tough on Wall Street. Today he's giving his support to two measures critically important for making sure the Street doesn't relapse into another financial crisis: (1) separating the functions of investment banking from commercial banking (basically, resurrecting the Depression-era Glass-Steagall Act) so investment banks can't gamble with insured commercial deposits, and (2) giving regulatory authorities power to limit the size of big banks so they don't become "too big to fail," as antitrust laws do with every other capitalist entity.