As weird as this election has been, anything is possible, and it seems nobody really knows anything for sure.
I wonder, if the repubs try to wrestle away Trump, and give it to Cruz, or if Cruz decides to run as an independent, and Hillary only wins with the super delegates, or Sanders just opts to run as an independent too, I reckon a 4 way race is really possible  

I think if this happens it will be Sanders, as he seems to have the most enthusiastic supporters.