"At the beginning of the 16th century, Native American population was estimated at 5 million. By the end of the 18th century, this had dropped to about 600,000. That this is tragic is inarguable. However, the Communists wiped out about 80 million of their own citizens--not counting deaths related to war--in less than a century. This should not be glossed over either."

Well over 90% of the Indians that died were killed by disease. This wasn't anyone's fault, simply the consequence of foreign populations coming into contact with each other. The tens of millions of people killed by communist regimes was intentional. These people were starved, shot, bayoneted, or murdered by other means. I think that makes a big difference.