People are really surprised about this?
Of course many white Sanders fans are going to vote for Trump if Sanders isn’t nominated and Trump is.
I’m bad at political analysis, but anyone who didn’t realize this is missing so much that should be utterly obvious. Trump and Sanders have positioned themselves and many see them as voices for the voiceless; they are both candidates that have cross-aisle appeal for this very reason.
And this reason is why Hillary Clinton stands zero chance in the general ceteris paribus if Trump is the nominee since many Bernie supporters — say 15 to 20% — will then swing to Trump.
I think Clinton’s chances of being nominated are nearly 100%, but her chance of defeating Trump if the Repubs don’t find some way to knock him off his perch are 10%. (She’d beat Rubio or Cruz easily, though — and the Repubs would rather lose the election than to allow Trump to gain that power.)