No, he can't be VP exactly because he cannot become the P in place of a downed P.I know you have term limits that one person can only be elected president for 8 years (22nd amendment), but does that limit Obama from running for VP? Could he then serve as president if something happened to the elected President? Could Trump do this in 2024?
Trump could run for VP in 2020, as he still has a term of eligibility. If he wins in 2020, he can't be VP in 2024.
This is well outside my scope but isn't Secretary of State in the line of succession and a workaround was created for Henry Kissinger as he was ineligible to be President? Couldn't a similar thing also happen in this hypothetical or am I comparing apples to oranges?
that's my take... he can't get elected as President (clearly), and he can't take over the role either. (less clear).. so, the line of succession just skips him (which apparently has historical precedence)