[dragonwriter]

> Is there an age that is too old to be a CEO/President/Senator/leading figure?

Not really.

> Are they necessarily out of touch, lacking in resiliency, not forward-looking, or any of the factors we look for in our leaders?

No; The statistical probability may be higher with age, but we don't elect an age and get a random person of that age as a leader, so that's not important. Filtering for that is what election campaigns, executive search processes, etc., are for.