He will. The thing about Democrats, is that they are cowards mostly. When it come to maintaining their power, they'll do what he says.
The thing is Bernie will ignore much of the Democratic moderates for the first year, and use Executive Orders, then-campaign hard for Progressives.
He will use the bully pulpit the way it should be. We in the progressive movement realize that Bernie winning is just the beginning of the fight.
This is long term change, not come by night.
We won't give a flyin flip about him. We'll move to get in more progressives. Look at Canada, Germany, and the UK. When it comes to moving moderates, after you make something the people want. Threaten their jobs.
I know it sounds mean. But hell these Democrats are not what the majority want. If they did, Bernie wouldn't be doing so well.
Also, who gives a shit about what John Delaney, a Healthcare shill thinks. He literally ran on "We can't do that!"