Being incurably optimistic and also probably just quite stupid, I'm still extremely bullish Rubio/Clinton and bearish Trump/Sanders, even after tonight, when Trump creamed the entire R wing yet again.
There was clearly lots of movement in SC in the last week or so as the race reacted to Christie's and Fiorina's dropping out. There was also, I still believe, at least some tactical voting as moderate voters finally realized Jeb was a dud and Kasich nice but ultimately too "who?" to win.
And yet none of those votes went to Trump. He's was, as I recall, basically at 30-35% at SC for ever, the same people who said they were voting him in December are the same ones who did tonight. I still think he has a ceiling and he's almost hit it. Let's assume that anyone voting Jeb in this climate would have gone for Rubio otherwise; that puts him almost level with Trump. If and when Kasich runs out of money, Rubio's in the lead. Cruz, now, Cruz is the million dollar question - if he goes out, where does his support go?
The basic fundamental of the R race hasn't changed - it's still essentially a coordination problem to which the consensus answer is increasingly obvious each day.