Bernie starts off by pulling off a shocking win in IA. Crushes HRC in NH. Manages to push the momentum into NV. HRC still wins SC by a good margin. Super Tuesday is similar to real life, except Bernie pulls out MA and breaks 90% in VT. Bernie manages to pull out close contests in IL, MO, and KY in the Midwest, and also CT in New England. He sweeps New England and the Midwest save OH, while HRC still cleans up in the Deep South. Bernie then ends up winning the entire West save AZ, and here's how it happens:
In late May/early June, Bernie and Trump agree to hold a debate before CA and the final states (I know it won't actually happen, but don't wake me up from my dream). Bernie puts in a YUGE performance and dominates Trump on the issues. This sends a wake up call to Dem voters and the Dem establishment that Bernie is the candidate to beat Trump in November. Bernie sweeps the remaining primaries. Bernie barely gets the nomination in spite of many superdelegates remaining loyal to HRC. Bernie wins in November.