WHile this is a very enlightening, and interesting thread.. I think the core question was phrased poorly and started a base assumption that no-one has jumped off of yet.
The threads core assumption is that might makes right when it comes to being a ruler.
Take a break from that for a minute and consider, while seated on the throne..what skills/abiities does a *good* ruler need {good not in terms of alignement

}
- Diplomancy - to convince people to go your way
- Intimidate - another way to convince people to go your way
- Sense Motive - to check for when folks are lying to you
- Bluff - for when you have to lie back
- Knowledge: Politics - So you know what the court, barons, Houses, etc.. might try
- Knowledge: Local - so you know what your citizens are putting up with
- Knowledge: Religion - to keep tabs on those pesky clerics and thier ideals
- Knowledge - Arcana - understand the abilities of the mages, both freind and foe
- Knowledge - Dungeneering - understand the threat facing you from the critters in the world
- Knowledge - War - understand the conventional threats facing you from neighboring kingdoms
A couple ways to do this,
- be a Rogue or Bard and spend your entire career focused on ruling...
- be an NPC classed Aritoscrat or Expert and spend your entire career focused on ruling..
- be the figurehead of an organization/group that advises you on all the areas you lack knowledge of..
This means the default setup for ruling is a group of advisors who have some measure of personal power themselves and support your existance as the ruler.
The rare setup would be a single individual who is capable of all the above on thier own. If they are not capable, any one of the factions they do not pay proper attention to will take advantage of the situation to 'save' the country from the evil despot and install a fair and proper ruler..who just happens to be a figurehead for their faction.
Lots of stuff in DnD mess with what we would consider 'politics as usual'.. but not really that much. Raise Dead only affects things if the assasinated target has freinds
One of the things that mess with 'politics as usual' is the poorly crafted non-combat rules in the D20 system. Check out Penumbra's "DYNASTIES AND DEMAGOGUES" for a much more detailed set of rules for running politics.
And.. for an interesting take on politics and death in a fantasy world, read Stephen Brust's Taltos novels..
