Logic dictates that in order for the party of the rich to garner votes that party would like as many Americans as possible to be rich. That same logic dictates that in order for the party of the poor to garner votes that party would like as many Americans as possible to be poor.
Or to put it the way my Father used to say it:
The Republicans are the party of the rich.
The Democrats are the party of the poor.
The Republicans want as many people as possible to be rich.
The Democrats want as many people as possible to be poor.
Which would you rather be - rich or poor?