What if both Biden and Warren had also run in 2016?

[The Undefeatable Debbie Stabenow]

If Sanders and Warren actually both ran (which, as others are mentioning, was a pretty unlikely scenario in 2016), they would prevent each other from seriously competing with Biden and Clinton. (This isn't so much the case in the 2020 primary because Sanders already has a base of support he didn't have going into the 2016 primary).

I do think that Hillary would still win. Although Biden may have been a tad sharper even just a couple of years ago, I think she would come out on top in the debates, and despite Biden's rank in the administration, I think that a plurality of Democrats believed that she, not Biden, was Obama's righteous successor (partially because of her painstaking 2008 loss).

Not to mention that Hillary pretty successfully walled Biden out super early on by snagging crucial donors and hiring lots of Obama's high-level staffers.