Great convictions are a start. but in order for them to actually pass legislation, they need other congress members to vote for them. and that's where the dirty tricks start (I wont vote for your X unless you vote for my Y, etc).
I guess I'm contradicting myself a bit, because I said "name one" without acknowledging that it takes a majority in congress to pass anything. So yes, Warren and Sanders have the courage to face corporate interests. Thank you. I just yearn for the day where shareholders of XYZ get a 30% haircut because laws were passed that reigned in their company's behavior.