It is really quite simple. A small number of Republican politicians get money from the super rich to run a campaign which appeals to the poor or nearly poor who then vote against their own interests, and meanwhile the  interests of the rich are enhanced and the small cadre of politicians have some semblance of power.

But the context is that the Democrats did not give these voters any alternative (we all felt it).

Now, i I know it is not that simple, but it is a good starting place.