1. Dem Nominee: Elizabeth Warren
2. President: Elizabeth Warren
Elizabeth Warren for President, and Bernie Sanders as VP.
Warren is the only one with a coherent plan, the knowledge, and the experience, to get America back on track, and back in good graces with the rest of the goddamn world. She's vibrant, intelligent, respected internationally, and compassionate.
There are a lot of problems we need to solve, and having a VP that was an effective legislator and champion of logic and reason - instead of just being a figurehead - would be an exquisite thing.
Bernie is too old to be President, and will likely die his first term in office (either VP or Pres). Not to be shitty about it, but the dude is in his 80's, and the office ages people dramatically.
This would also give Warren the ability to appoint a new VP if/when Bernie passes. (With approval by Congress. But Moscow Mitch will be dead by then, too. So Congress may get back to work, eventually.) So Bernie gets the VP nod, does his work on disempowering the corporate class and 1%, passes away, and then is replaced by someone like Andrew Yang, who can be tuned-up as VP to run for Warren's seat after 8 years.