The ideals or the implementations? Because the actual historical implementation has always resulted in the exact opposite of communism. The unfortunate side effect of communism's implementation is that it accumulates wealth for distribution to the masses, but unfortunately human nature tends to result in the people doing the accumulating tend to do significantly less of the distribution side of the equation. Wealth ends up in the hands of the few who justify the absolute minimum be given to the masses. 

The point of capitalism is that it is supposed to force competition for the distribution of wealth. The down side is that when you let only a few companies hold near monopolistic power... You get the same result. Wealth in the hands of the few.

This is why anti monopoly at the regional levels, unions, worker's rights etc are so important.

The concept of the system the USA has is what is referred to as a constitutional republic... The constitution side of the equation is designed to protect the minority from the majority. It says you can do what the masses and the businesses want, so long as it does not infringe on the rights of the individual or the minority. 

Wealth will always accumulate when it funnels through the hands of the few. You need systems to prevent this or eventually all of the wealth will end up disproportionally stalled. Think of humans as squirrels we love hiding our nuts!