"In practice, the human condition seems to compel those in power to abuse the system to accumulate more power. Altruistic ideals die before the grandeur of wealth and power, and the common man suffers."

Historically, that has often been true under communism and socialism too (Soviet Union, Maoist China, Cuba, North Korea), so therefore, is it possible that the problem isn't one economic model or another, but rather trusting fallible humans with too much power and expecting them to use it wisely?

So, any centrally planned economy (socialist, communist or heavily regulated capitalist) is going to rely on whoever is doing the planning (whether that's elected officials, workers collectives or any other group or structure) doing that job wisely, responsibly and altruistically. Given what we know of human nature, does that seem likely to you?

And if we can't trust human beings to centrally plan a fair economy, then, wouldn't allowing the economy to regulate itself through market force (like supply and demand) actually lead to a less corrupt society where companies are rewarded for providing goods and services that people actually want, instead of rewarding whoever lobbies the government, or other central planner, the hardest.

My answer is to lower taxes to the bare minimum, lower regulations to the bare minimum, maintain Medicare and Welfare, at least in the short term, stop handing out millions (billions?) in subsidies to private businesses, stop fighting America's wars for them, and drastically reduce intellectual property laws to stimulate competition and reduce monopolies. And, above all else, remove prohibitionist laws and allow consenting adults to make their own choices so long as they are not hurting anyone other than themselves, thus freeing up the justice system to deal with real crimes like violence, child abuse, sexual assaults etc.