There's simply no way in hell that a bank whose deposits are guaranteed by the Federal government should ever be permitted to engage in risky -- even speculative -- lending and investment practices. The whole purpose of Glass-Steagall was to separate the commercial banking industry from the mortgage banking industry. The operating environments for these two industries are so different -- largely due to different tax laws and the aforementioned depositor protection -- that they should function completely separately.
We hear all the time from the extreme left that there was "deregulation of the banking industry in the late 1990s", and it never seems to matter that virtually all the Glass-Stiegel act remains while mountains of new regs were passed (like forcing banks to loan to penniless minorities).