This is an easy one.
The Republican party is the party of the Investor Class. If we were talking about purely the interest of the working class vs. the interest of the investor class, the Democrats SHOULD win every election, for no other reason than the working class is much larger. And in fact, they pretty much did between 1932 and 1968, the only respites being when the Republicans nominated a sensible war hero who moderated the GOP's love of greed against actually standing up for working people.
Then two things happened.
1) In 1968, the GOP realized they could scare a comfortable white working class by playing on their racial, religious and sexual fears. Vote for us, or you'll get killed by a Black Panther or a drug crazed hippy like Charlie Manson.
2) The Libertarian Crazies actually managed to sell a bill of goods to the working class that the sensible government programs that created the middle class was in fact holding them back.
As utterly horrifying as Trump is, he's just the undiluted version of the toxic shit the GOP has been serving up since Tricky Dick.
A kid I grew up with works as a garbageman for the City of Chicago. And he essentially makes $72,000 a year picking up trash. Which is good money for someone with no college degree. But the ONLY reason he enjoys that wonderful lifestyle is because a Democrat fought for him to have a union and get a good union wage. If he worked out in a Republican Suburb, he'd be making $17.00 an hour and probably working that truck by himself.
Yet he sits in his truck all day, listening to Hate Radio, and repeating whatever Rush or Hannity says like he had an original thought.
This is what makes the GOP kind of evil. They know they are appealling to the worst in human nature, they know their policies will be a shit sandwich for most Americans...
And they don't care.