The people in the states he won in the primary were well aware of his "Socialist" label by corporatists and right-wing extremists.
As the results showed, it didn't phase them.
BTW, it's all about the Electoral College in the general election. There's no reason why Bernie wouldn't have won the states Hillary did. Had he also carried over Iowa, West Virginia, Michigan and Wisconsin like he did in the primary [[plus I'm sure Pennsylvania would have definitely gone blue), he would have easily surpassed 270.
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