Growth comes from many sources. The supply-side economics wing of the GOP would claim that lower taxes and smaller, less intrusive government will allow for a higher private sector growth rate. There may be some truth to that, although the effects are probably limited compared to the development of disruptive new technologies.
Just yesterday I was talking with some friends about the disaster that neoliberalism has been.
I see billionaires as "water-balloon" (wealth) hoarders, and I see taxes on the rich as thorns on bushes. If the politicians ever wanted to make "trickle down" work, then we need thornier bushes and to make it impossible for rich people to not go through thorny bushes.
But the whole deregulation craze has made it so that the billionaires don't even need people to help them protect their "water-balloons"...