“””A full investigation by Congress is absolutely necessary,”””
I am not sure a full Congressional investigation will uncover anything that is reported to the public. Washington DC is too invested in keeping secrets from the public.
What a full Congressional investigation will do is to put water on Obama/Jarrett plan to have a shadow government. Obama has been put on notice that if he persists in obstructing government, he might spend some jail time.
It is so unusual for a former president to stay in there and play the game of thrones that I believe it is proper to get rid of the former politeness that kept current governments from holding prior administrations accountable for their misdeeds.