Trump may, indeed, have a ceiling around 33-35 per cent of the primary vote. But where are his rivals' ceilings? Marco Rubio bounced back from his humiliation in New Hampshire to a distant second place. But, considering he had the much coveted Nikki Haley endorsement, that's not an impressive result - and even if every single one of Jeb's votes [goes] to Marco (which they won't - because John Kasich has all the more reason to stick around till Ohio)[,] that still doesn't get Rubio near Trump.
As for Ted Cruz, the Palmetto State has to be accounted a disappointment. We were told that New Hampshire was too "moderate" and "libertarian" for his particular brand of conservatism and that South Carolina was a much better fit. But he came in exactly the same place - third - and this time without any delegates.
~As for the Nevada Democrat primary, one is sympathetic to Bernie Sanders because he's operating within a much more corrupt party machine whose superdelegates have already been snaffled up by Mrs Clinton. But that's all the more reason why he needs to win these caucus states instead of just kinda sorta almost tying Hillary. The difference between Trump's hijacking of the GOP primary and Sanders' attempt to do likewise to the Democrats is the difference between a fellow who means it and a guy who lacks the killer instinct.