Did Intellectual arrogance lead to the murder of 100 million people at the hands of Stalin and Mao. Is that same arrogance alive today?

good response, i agree with much of what you say but i fear the core reason why communist governments resort to genocide is because an individual human life has no value or worth to an athiestic philosophy that is only concerned with the community as a whole. Why i still think our founding fathers got it better than any other country. If the individual has inalienable human rights they can live truly free and society as a whole will prosper.
In an earlier post i pointed out that one of the core faults of Marxists philosophy is the very core claim that humans are social animals. If everything in the athiest philosophy can be reduced to mere chemical reactions...then isnt that feeling of community simply another chemical reaction? and as such....purely meaningless?

I don't believe so. As a humanist myself I have a strong drive to provide service to my community. I believe a country where we all have a drive to make it better is a good place for my children to grow up in. I am, and know, a good number of atheist service-members, and none of us live any bleaker or meaningless lives than the faithful service-members of my unit. We find awe in nature and community just as any person of any faith would. I have a deep devotion to members of my unit, and they to me, because we are a team of professionals who have proven their worth to each other in combat and in training. I believe, at least in the sense of purpose and being for me, that transcends any religious dogma. I take a person as a person, I don't make a judgement on Christians or Jews or Muslems. Compassion for each other as humans is where I'd like to see more people coming from.

Most of the deaths were blunders not downright assassinations. Look up the Wikipedia entry for Great Leap Forward. Mao's attempt to industrialize the agriculture industry. It's very evident that communism fails not because of some inherent evil with the leaders (who believed they were doing the right thing) but within the system itself. The plan called for plows and updated methods of planting, but when the results didn't come in the regional governors didn't report the truth (that the plan had failed, crops didn't grow) if they had done so they would have been relived because none of the other Governor's failed, (see the similarities with the VA) It took years of no deliveries on food, even visits to the farms were staged so Mao and his group didn't know the truth. Five years ~60 million died from starvation, before communism had to rethink their ideas. That is the danger with all Socialistic systems of economy, in Capitalism the market corrects itself, in Socialism the Government has to admit they are wrong and correct themselves which is not an easy political process.