Since the financial disaster in 2008, there have been few prosecutions of the bankers who are ultimately responsible. Without this pressure, I believe the US is setting itself up for further disasters.
Although Warren has spoken out somewhat on the issue of banking, she has not been forceful enough (to my mind) on the specific point of calling for further prosecutions. I have not seen articles from the New York Times indicating that she is, for example, demanding that Holder step down. Perhaps she fears dividing the party.
I would like people to fill in the poll, to help me gauge the level of support here for campaigning on this issue.