I think that the answer is no to both. Although there are a lot of problems, I think that the checks and balances would keep that from happening. However, if we had a major war, then it might be possible.

I'll attempt the second question first. (So I ass-backwards, sue me)
I think we learned a lot from the great depression. Recessions are still quite possible, happen from time to time, and are actually a normal part of the economic cycle as far as I have observed. While a major catastrophic event could cause econimic collapse, I don't see the condition of severe depression coming about again in some other way short of this.
I'll note here that I am in no way an economist, I just observe and think for myself.
As for the first question: In order to establish such a government system the first thing that must be done is to disarm the citizens. As Jefferson said, "the best governed society is and armed society". Our forefathers saw that by allowing the citizens to be armed, the government could be held in check to a certain extent. They didn't protect our rights to arms to go out and shoot rabbits but to shoot politicians when they try to oppress us.
OK, I know the topic is far more complex than this simple answer, but it is an important point. The primary reason the Japanese didn't plan to continue their surprise attack from Hawaii on to the west coast of the US was they knew they wouldn't stand a chance with so many civilian guns against a relatively small invasion force. This was admitted by the Japanese themselves after the war.
While the American people have their problems with the extreme left, the extreme right, the whole annoying politically correct garbage movement, and other social problems we are still a very independent people who would not sit still for an outright coup of the democratic government (or our version of one at least).
I'll say here that I am not a political student or expert, and not even a very potitically motivated person. Personally I think politics these days is a shameful mockery of what it was intended to be in this country, but that's beside the point. I am simply saying again, these are my personal opinions, arrioved at by personal observation, life study, and free thinking on my part, and not the regurgitated pap many spew forth without a modicum of free thought. I hold no allegience to any political party, lobby group or political organization. SO take it for what it's worth (probably not much to those who dedicate their lives to the study of such nonsense).

Very interesting questions!
This country will NEVER be under absolute Socialist control.

I don't feel free enough yet to answer the part of Fascist control!

I used to love to hear my mother, raised on a farm, talk about the tramps that would come to their door for food during the depression. And I've stood in the modern day soup lines.
But this actually a very rich country, I think.

To #1

Why do people vote ? Two reasons - 1) My vote counts, 2) I want to change things. (among other reasons).

Assume a citizen's vote becomes so diluted by population, special interests, and dangling chads, to approach zero. Further, what if the US reached a level of affluence, such that a great majority thought "You know compared to the rest of the world I've got it pretty good - I shouldn't complain".

Why does any civilization fall ?

Yes it could happen. But maybe it is not an either/or - maybe we are leaning that way, right now ?

I'm not sure if it's Maggie, my computer, but I can't see the picture

You're right wise fawn. I have deleted it. The comments I was to make are too economically jumbled for even me to make sense of yet. I am letting it go till I can be coherent in my rant.
By staying out of the replies I hope to allow people to offer information they feel comfortable with and not feel they have to defend their position for a change. Each opinion on these quetions is as valid as the next, and thought on it is the goal.

[off topic] Wahkonta please post something in your conspiracy column about the trilateral commission and/or skull-bones unless it has been done to death ? Feel free to delete after you get this message, or ignore.

It has been overdone, but I have some very eclectic information on this groups truer origin. As my methodology is to pre-date 'institutional' history, I have a founding date for "The Sons of Liberty" which takes them back to Boston colonial government in 1718 as "The True Born sons of Liberty". I have done the same with freemasonry and the Skull& Bones, or 'Russell Trust', which claims a incorporation date of 1832. I can take them back to a predecessor group in New England to the 18th centuryand the plot to overthrow the fledgling American government by start of War of 1812. Any time one shops or eats at Lechmere, Denny's, Perkins, they are at a skull&bones originated business. Sometime I'll put it up, but am going to put it on my free web page first as a copyrighted piece in my book on history being 2d drafted now. I recommend going to http://www.fleshingoutskullandbones.com for the recently completed compilation of materials on this group by Kris Milligan. Also Webster Tarpley discusses the frat as it relates to Bush, Sr. and has free info. at his site (punch up his name on a search to get it).