Of the bunch, I'd probably like to see Bernie get the nomination, because his "Democratic Socialism" alienates Clinton Democrats/swing voters and he doesn't race-bait enough to appeal to the BlackLivesMatter and La Raza crowd. Harris would be good too - her blatant race-baiting will appeal to the BlackLivesMatter and La Raza crowds while alienating moderate swing voters, albeit for completely different reasons than Bernie.
So hope for either Harris or Bernie if you want a Trump landslide in 2020. It isn't so much that the people who Bernie or Harris alienate will vote for Trump, rather, they just won't vote at all.