Why would he? Trump and Sanders’ protectionist stances are almost identical. Whether it’s Trump being the Egyptian Pharoah in charge of white slaves picking tomatoes or Sanders’ Organic U-Pick market, it’d work out just about the same, at least as far as the price of things will go
Take a peek inside of Sanders’ sites. The anti-Clinton rhetoric there and in the Trump sites are identical.
It’s white north vs white south for the most part.
That’s not to say that either side is wrong about her… just that the dislike is equal.