The post you are responding to is probably referring to the Gramm–Leach–Bliley Act. According to some, that act (signed by Clinton) was (somewhat) responsible for the financial crash. But this is certainly a matter of dispute.
To expand, this law allowed investment banks (e.g. Goldman) and commercial banks (e.g. Washington Mutual) to do what the other could. Effectively this allowed the mortgage backed securities that were a major player in the financial crisis to be created. There were a lot of other issues that contributed to the crisis, but (as far as I'm aware) the main mechanism used would not have been possible without this deregulation.
Eh. It allowed banks to have in house investment banks. They still needed to have walls that dealt with conflicts of interest between the two. Whether the walls work all the time can be disputed.
But you seem to have offered no substantial link to the existence of MBS securities and the repeal of Glass-Steagall. so your conclusion, that arbitrary deregulation, lead to the existence of MBS securities should be even more disputed.
MBS are probably more clearly linked to the complete takeover of the mortgage market by the government. if you turn debt into a commodity you can divide it up however you want. and you turn debt into a commodity by guaranteeing it.
