[robbedpeter]

This is a valid question for different reasons, too. I have a problem with the speech and behavior of immortal characters in books - why would a 300 year old powerful vampire behave like an immature emo teenager?

There's a reason we associate wisdom with age. The more times anyone of reasonable intelligence makes mistakes, the more opportunities they have to learn, and their behavior changes according to the degree to which they take on the lessons of life.

One big danger of immortal dictators is the simple fact that they'll stop learning. Through wealth and power they shield themselves from the consequences of mistakes, getting themselves and their people stuck in a local minima.

Imagine immortal Mitch McConnell, ever increasingly wealthy through passive income, maintaining power and privilege for his constituents and thus his hold on a senate seat.

If life extension pans out, liberal societies will have to impose term limits in a serious and well considered way. Humans aren't ready for the existing pace of technological development, and we're going to encounter an exponentially increasing number of problems, like the politics of immortality. The best thing we could do would be to maximize freedom of expression and minimize the duration of social institutions to achieve sufficient maneuverability to adapt to modern life.