I think they should each chose the other as their running mate.
While I do think Trump is a bit of a lunatic I also think hes talking out his ass and has no real intention of following up on a lot of his talk.
Sanders on the other hand is pure business when it comes to trying to get things done.
I am not even 100% sure why this appeals to me but the thought of a Sanders presidency with Trump as Vice could possibly wake the political scene up to the fact that a lot of Americans are beyond tired of the same old same old.