Reasons I support Primogeniture:
- The power of electors can be leveraged into an independent power base, leading to struggles (they can request promises in exchange for support)
- Electors will favour candidates they think they can control
- Disputes over methods of succession can produce war. (What are the exact rules of who votes, who is eligible to be elected, etc? Who counts the votes, where is it held, how much notice is given?)
- Composition of the electorate is unstable. The historical trend seems to have been from popular elections to narrower councils of the elite (e.g. folkmoots to the wintagemot) The mechanisms driving this evolution is unclear, but smells of politics.
- The heir should be raised to rule, not to compete. What are the disappointed candidates going to do with the rest of their lives? (cause trouble would be my bet).
- The King should not believe his power derives from his personal merits. It is a job which has landed on him, not been awarded to him.
I am more open to a compromise of the King nominating his successor. Even that is problematic — Edward the Confessor’s and Henry I’s nominations caused wars, and Edward VI’s nearly did. On the other hand, their right to dictate the succession was never really recognised. I am particularly worried about a geriatric King being pressured to nominate towards the end of his life — a highly unstable situation.
Failing that, what to do about the prospect of an obviously unsuitable heir?
First, I don’t see that as a large danger. A King does not require high intelligence, selflessness, strength, but just a basic level of sanity, and an above-average level of self-confidence and drive. His upbringing ought to provide the self-confidence and drive, so the only truly unsuitable heirs would be the grossly stupid and the insane.
Nevertheless, these are dangers. My feeling is that in such exceptional circumstances, the right solution is an exceptional extra-legal ad-hoc action to bring an alternative to power. This is problematic because it weakens the authority of tradition for there to have been exceptions, but any kind of formal institution for settling the matter is bound to grow beyond its intended scope and bounds — institutions always do.
The laws of England and the Commonwealth are in the process of being changed to pass the succession to the first-born regardless of sex. As I have written before, I support this change. Ideally, we would have Kings rather than Queens, but (Henry I again), it is better to have a certain succession than the most suitable candidate.