There are many "different" political theories.  They come in a lots of different names.  There was actually a golden era of the creation of poltical theory, starting in about 1600 and lasting until about now.  Before 1600 about the only political theory was the divine right of kings.  And it was good to be the king.

Basically, for all of recorded human history the idea was that the leaders are annointed by God or the Gods to rule over His/Their people -- and all else be damned. 
By about 1600 there began the Enlightenment -- when new ideas really did come to the fore.  What transpired in the beginning was a flowering of individualistic ideas -- though often just as willing to slaughter anyone who didn't agree.  The Pilgrims, the Huegonots, Calvinists and others -- which all called into question the divine right of Kings.  Alas they only renamed the idea -- and called it the divine right of the leader of the particular group. The Pilgrims weren't nice to non-Pilgrims, despite their call for free religious belief.

But earlier, in two places there arose a certain level of free-thinking that said not only does the King not have the right to rule and slaughter -- but neither does anyone else.  The first inkling of these ideas surfaced in history in the 1400's -- with John Wyckoff in England and Jan Hus in Bohemia.  Both were against God, King and Church ever ruling people.  They were snuffed out.  But like Pandora's box, the idea had sprung loose.  The ideas couldn't be put away. 

Over the next few centuries the two ideas slugged it out.  They are still slugging it out, but the Divine Right has already lost.  It's a matter of time. The Declaration of Independence was the first national expression of the freedom idea.   It has now so permeated the world that even the most dictatorial of dictatorships at least pays lip service to freedom. 

Nearly every "new" political theory from Marx in the 1840's until folks like Castro in Cuba today has been but a restatement of the divine right by the use of other words.  The idea was still that the "King" got to rule because of some "natural" or "Divine" or "scientific" reason that was somehow floating through the air and landed on the Dear Leader. 

It is only a minority of people who claim they believe this anymore.  And most of them probably know the end is near, but they hang on because their place in the future is undetermined.  And they want to live good now; after all, it's good to be the king. 

The political theory which will remain is actually more of a general principle.  All men are created equal, and are free to pursue their happiness in liberty.