"Communism is not evil, it is an ideology." I agree, but it is the implementation of the ideology that is evil. You mention that it works for small groups. That may be so because it is possible for small numbers to agree to the same thing. In sorting my way through all the information about `failed kibbutz,' I ran into this counter story:
 http://www.zeek.net/710kibbutz/
So your assertion appears to be correct for these groups and others that label themselves anarcho-socialists.
On the other hand, the Marxist-Leninist brand of communal paradise saw the need to expand this idea into a much larger arena than a few people who agree to join together.

The basic premise, I believe, is that in order to alleviate the poverty that one sees in the world and the capitalist system - remove the divide between the wealthy and the poorer classes - an attempt must be made to rectify the situation by those who feel deeply that this is an injustice. This cannot be immediately brought about by democratic means and revolution is necessary. The `workers' must join together and take power from the wealthy, divest them of their lands, businesses and wealth.  The product of all labor is then shared equally to the benefit of all (the original beautiful idea.)

That those who resist must be killed or imprisoned is a necessary evil, but once everyone agrees to cooperate, the result is paradise on earth. Well, everyone will share equally and there will be no favored classes. The vast majority of attempts to install this ideology, whatever one wishes to call it, have failed and the initial `necessary' purges never seem to end.

"The main problem with Communist ideology as a form of government is the age old problem of power and corruption. " I believe the problem has its origin deeper in the human make-up. Human nature cannot be changed by social programs or pogroms. You will never eliminate envy, greed, pride, etc. Elements of human nature cannot be bred out of the human.

  "Stalin usurped control after being granted it by the people, essentially creating a dictatorship.  Trotsky, a communist idealist opposed Stalin and was killed.  The Soviet Union, a military based dictatorship was born." A closer reading of history will reveal that the `people' started disappearing long before Stalin stared his monstrous dictatorship:
"Academic Marxism hardly even bothers to ask the question, except to play the usual good-cop, bad-cop routine: humane Lenin, evil Stalin, etc. But the failure of Marxism-Leninism goes deeper than its accidental betrayals. It is the ideology itself ... that contributed to the stupefying tally of 100 million violent deaths under the hammer and sickle -- the largest ideology-driven genocide in history. Mass murder, they point out with numbing archival thoroughness, was made the center of the revolutionary state in 1918, not 1931, and by 1920 Lenin had killed more people than 90 years of czarism combined. He was, of course, spectacularly outdone by subsequent "Marxist" dictators who thought history was on their side."  - This is from a review of "The Black Book of Communism."
http://www.amazon.com/gp/product/0674076087/ref=cm_cr_pr_product_top
The authors of the book list in 800 pages the crimes attributed to what they call Communists states. The carnage is horrific.
Another, much briefer iteration of the horror:
http://www.victimsofcommunism.org/history_communism.php
"Because many people during the McCarthy era had their lives ruined because they were affliated with, or accused of being affliated with, a communist organization." This is pretty much blown way out of proportion. I could ask you to name some. Please.
The FBI had accumulated the names of many persons who were known to be on Moscow's payroll. The Communist Party of the United States was funded by Moscow. There were, of course, many very fine people who joined the Party because they believed the Communist ideal of economic and class equality. They were free to do so. Indeed, as the Soviet Union was our `ally' during WWII, many of these same people entered government or were allowed to remain in positions of power and influence even though the FBI tried to alert the administration of the danger of espionage. Usually, however, the most dangerous individuals were not openly in the Communist Party, but `underground.'
Elizabeth Bentley and Whittaker Chambers were underground agents that ran espionage rings and broke with Stalin's `Communism' after having devoted years to the idealistic beliefs. The reality of the purges and evil that the Soviet state had become forced them to make difficult decisions. At the risk of themselves being killed, they decided they must inform on those whom they knew presented a danger to the government of the United States. Chambers gave a list of names to Adolph Berle, an assistant Secretary of State as early as 1938! Roosevelt ignored this. Indeed, Alger Hiss, named by Chambers was very influential in the administration, accompanying Roosevelt to Yalta and assumed great responsibility in forming the U.N. Chambers' book, "Witness," is a great read.
Those who saw the danger could not believe that spies on Moscow's payroll were allowed to continue in their offices for years after they had been accused. There were so many agents, sympathizers and fellow-travelers that they were able to cover for each other and, in many cases, squelch further inquiry. They were so well entrenched and respected that you will find them defended to this day by leftists.
 "Where there Soviet spies in the country? Sure! did we have spies in there country? Of course, it was all part of the game." This `game' was one that pitted one participant that would kill millions of innocent people to expand its power against one that valued freedom and liberty. Yes, one was free to join any organization one wished. When some members of that organization were committed to the overthrow of the government of the U.S., that `game' became rather serious to some lovers of our freedoms, some patriots. When those committed to championing an avowed enemy are in your own camp, its time to ask why, how long, how much damage have they done, and what can we do to root them out.
"The atmosphere of insecurity and fear created in the country was more undermining of our constitutional values than any good that possible came out of it." I decidedly disagree. The only fear created was in those who feared being caught. The vast majority of Americans was appalled that our government had been infiltrated and was delighted that something was being done about it.
While there are no laws against belief in this country, when belief actively turns to overthrowing the government, the laws are in place. If you couldn't sign a pledge to be loyal to our government, then you shouldn't be allowed to work in said government. If you actively produced propaganda for an enemy government, shouldn't you be questioned about your beliefs? These were dangerous times and certain measures were necessary. What McCarthy trials are you referring to? Who was being tried?
Here, from someone infinitely more literate and concise than I:
"The symbolic rite of passage for 20th century American liberals was the period they have succeeded in labeling the "McCarthy Era." If Republicans had been half as rhetorically astute, we would in all likelihood know this time by a different name, as "The Era of Soviet Infiltration." The end of the Cold War has almost universally vindicated the charges by Republicans in the late 1940s and 1950s that Soviet espionage agents occupied critically compromising positions in multiple agencies of the U.S. government and the military. Despite the villainization of Richard Nixon, his target Alger Hiss was, we now know, guilty. The Rosenbergs were guilty. FDR's Chief of Staff Harry Hopkins was, in all probability, guilty. Staggeringly important secrets were passed by American citizens to the Soviets, including plans for both the atom and hydrogen bombs. There is simply no way to deny the truth that the communist conspiracy claimed by the Republicans did, in fact, exist and was consistently denied, dismissed, or provided cover for by the Democratic party.

Nevertheless, the liberal/left elite in this country has succeeded in perpetuating a dramatic myth that is flatly contradicted by the facts. The anti-communist crusade of Joseph McCarthy, by reason of its impoliteness and its incompetence, has become the secular Passion of liberalism, its sanctifying crucifixion, the basis of its arrogant, continuing, and utterly unjustified claims of moral superiority over the conservative opposition. (Lest you regard this as overstatement, please read "The Crucible," Arthur Miller's play about the McCarthyism of the 17th century Salem witchcraft trials -- as we all know, there were no witches/communists . . .) We are supposed to overlook the enormity of the fact that at the very dawn of the nuclear age, American citizens conspired to transfer the deadliest technology ever developed to the mortal enemies of their country. This terrifying event is supposed to pale beside the prospect of a Hollywood screenwriter whose career was damaged by his membership in the 'party' that led the conspiracy. It doesn't -- except in the minds of those who have never quite understood, and probably never will -- the sickening, murderous evil that was the Soviet communist state.

Yet the Democrats won the word war. The term 'McCarthyism' entered the language and has been kept vigorously and determinedly alive. It is, by usage, synonymous with fascism, because it has come to mean the ruthless persecution and demonization of an imaginary enemy for purely political purposes. And ever since the great Democrat Passion of the 1950s, this word has been hurled at every concerted Republican attempt to uncover any kind of wrongdoing in the left/liberal establishment." R.F. Laird, excerpt from:
http://www.instapunk.com/archives/InstaPunkArchiveV2.php3?a=1045
"It was hurtful when we interned the Japanese Americans, ...and it is hurtful no with the prisoners held without due process in Guantanamo...
.........and what people don't seem to realize is that the people that are most hurt, are us. "
I agree wholeheartedly that American citizens interned by the Roosevelt administration were absolutely wronged. I was born in an internment camp. That was wrong because my civilian family was interned simply because of our nationality and where we were. That was wrong and the Japanese internment was worse, since they were in many cases citizens - a true abuse of the Constitution, in my opinion.
However, prisoners in Guantanamo are prisoners of war and no country in history holding prisoners of war during a conflict felt any compunction to release them to fight again while the conflict was ongoing. So this is total BS.
I am in complete agreement that government has become too intrusive, too large and has gotten away with murder both figuratively and literally (Waco and the Branch Davidians.) That is why I am probably more drawn to libertarian views than other political persuasions. I also live in Texas, where some semblance of individual autonomy still obtains.
Hey, I had fun. Thanks for allowing my rant.
P.S. I had a less than sterling round of golf. As is often the case, however, I discovered something I had been missing in my swing on the 17th hole - too late to save the disaster - I barely broke 90.
Take care.