Why Wall Street CEOs have escaped fraud prosecution

There are a series of videos on this subject at this link.
I wonder if the current Republican supreme court would uphold a conviction in these cases.

http://www.pbs.org/wgbh/pages/frontline/untouchables/

At the time I posted this, the following was the most recent entry.

http://www.pbs.org/wgbh/pages/frontline/business-economy-financial-crisis/untouchables/did-wall-st-get-away-with-it-live-chat-wed-2-pm-et/

January 22, 2013
by Nathan Tobey

More than four years after the financial crisis, not one senior Wall Street executive has faced criminal prosecution for fraud.

Are Wall Street bankers simply “too big to jail?”

In The Untouchables, FRONTLINE producer and correspondent Martin Smith investigates why the U.S. Department of Justice has failed to act on credible evidence that Wall Street knowingly packaged and sold toxic mortgage loans to investors, loans that brought the U.S. and world economies to the brink of collapse.

So, after talking with top prosecutors, government officials and industry whistleblowers, what did he find? Is there a chance some prosecutions may still take place? What do we really know about the criminal cases that could be have been pursued? And what does this investigation reveal about Wall Street and its relationship with the government?

There is a question and answer chat.