Trump vs Sanders would be the largest landslide victory in the history of presidential elections. No one over 40 is voting for a communist in America. No way he gets even 30% of the vote on a national level. Sanders might have done ok if he didn't refer to himself as a socialist. People still remember the USSR (Union of Soviet Socialist Republics). In America, socialist means communism.
maybe, maybe not
I am over 50, the USSR collapsed when I was in college and is a dim and distant memory.
Sanders might energize millennial voters in unprecedented numbers.
Or, perhaps, it turns out as you say, a good spanking and reality check might serve to shut them up somewhat.
Only one way to find out.