In the United States, the republican party are advocates of trickle down economics. What it amounts to is basically “let the rich keep their money, when they invest it, the money trickles down to the poor”.
Now, Ive just realized the obvious problem with this.
Any person who invest money do so to grow their own wealth (obviously). When you invest, you want to get a return on your investment that is greater than inflation, anything else is a bad investment. But inflation can be roughly interpreted as the measure of Everyones wealth.
Therein lies the problem. The rich only invest in things that increase their own wealth faster than the population average. This means, that no matter what, the rich will continue to get richer while the poor keeps getting poorer.
The only way to stop this is for government to take money from the rich to give to the poor. The simplest way being to have higher taxes on rich than on the poor. Good luck selling that idea to rich old white dudes in the US congress and senate.