Plato was a deceitful hypocrite, with his so-called "Republic".  In our philosophy final the term we covered that (in the original language, btw), I got the first A+ the professor had ever awarded for butchering Plato with his own words.
By those words, his "Republic" is a farce, the sort of political piece put out to hoodwink others with wily words.  The whole foundation of the political entity rests on "certain noble lies" told by the "philosopher-kings" -- but Plato argues quite soundly elsewhere that one who tells lies at all is no philosopher, and will be unable to see truth.
Beyond that, the is no such thing as freedom in Plato's "Republic", there are only people assigned from birth to roles determined by those above them, and lied to to keep them happy.  Freedom depends on people deciding what they want to be; the Republic is all about telling people what they want to be.
The flaw in Laws is that he assumes the same thing that the monarchs of Europe did:  some divine right for the State.  The State has no such thing; it has no rights whatsoever because it is an artificial entity.  We are free by nature, because we own ourselves -- that's inherent.  The only reason we are bound to follow is our own; while that means we have the option to muck up our freedom, it is not an excuse for limiting it.
Plato didn't truly believe in reason, or he'd have shown that if all followed reason, we wouldn't need government at all.  But he skips straight to an imposition of absolute authority based on lies.  His philosophy would have served as a great foundation for the Confederacy:  the great landowners as philosopher-kings telling everyone else what his or her place in life is to be, and that they should enjoy it -- slave, or otherwise.
		
		
	 
Well, I'm not going to say that Plato was deceitful, but he was a hypocrite (I'm sure it wasn't driven out of pure malice, though, which your tone indicates.)
I think Plato believed a lot like the Founding Fathers of the United States; that the "common man" just isn't capable of ruling himself well and needs someone to "look out for him".  (The early US Senate seats were voted for by the State Congressional houses, the aristocrats/politicians, because their positions were considered too important for the "masses", many uneducated and unable to read and write, to vote in.  This is also partly responsible for the Electoral College system we still use today and why Presidential elections are determined by the EC and not the popular vote.)
However, his premise is essentially that greed is bad for any leader (a true premise), but his way of dealing with it was to essentially take the healthiest and smartest children at birth from their parents, put them in institutionalized (read: public) schools, and tell them they were the children of the gods/made of precious materials/metals.  In this way, they would be brought to believe they ought not seek gold or riches because they were more valuable than gold themselves, and that, now freed from greed, they could lead their people as the guardian ruling/military class, and they were to be trained in military and martial skills and tactics as well as philosophy.  From among this class would be found the greatest, best physique, smartest, and most powerful, and this person would be made their philosopher-king.  The lineage of the ruler would then be that when this person died, then instead of kingship being by blood, the next philosopher-king would be selected from the class just as the last had been.
...of course, if you didn't make the cut to get into this class, you would be relegated to a field worker and farmer, though you could become an artisan if you showed significant desire and proficiency.  Plato also saw the merchant class (which is what eventually allowed a middle class to develop so it wasn't all the rich/poor dichotomy of the ancient world) as corrupt and evil, seeking to actually make money on things.  
The thing is, Plato was right about a number of things.  Greedy leaders are bad and a runaway capitalistic system can be destructive.  However, his resolution to these problems was to lie to people and establish a class/caste system; not one based on whose family you were born to, but rather your abilities.  That means, if you were born today with the ability to be a painter, but really wanted to be a doctor...well, too bad, society demands you be a painter.  (Though maybe I'm mixing neo-socialist ideals into that, but I think that's the logical conclusion of Plato's Republic if said Republic were to exist in the modern age.)
In all honesty, I found Utopia to be far more interesting (though, in the end, equally in error.)  At least it amused me more.  ^_^