I agree with most of what you’ve said. But, to say that one president leads to another is a non-started because that argument can be made of many election cycles. Unfortunately, without a conservative windfall in the Presidency, we may be on a 8 on/8 off cycle for a while.
Historically, the Dems were DUE to take the WH in ‘08. GHWB was the first exception of a VP being elected after a 2 term POTUS in something like 125 years. You could have bet on it happening again. But McCain-Palin were ahead in the polls till the economic collapse in ‘08. Not that that’s worth a damn.