Let's suppose there is evidence that tRump colluded with Russia

[MedusaX]

6. While it would be unprecedented, I do believe that a legal argument could be made that

The protections afforded to the holder of the POTUS position are NOT applicable
to one who holds the position as a result of unlawful acts
&/or has used the power of the POTUS position as part of such unlawful acts.

Why?
Because the immunity is only absolute with regards to actions which are performed within the reasonable scope of the presidential duties...
And
Acquisition of the POTUS position through use of unlawful acts would not be within the scope of presidential duties....

Nor would utilizing the power of the position
to benefit a foreign country
as a reward for having implemented active measures as part of the coordinated efforts
which achieved the shared objective
of both the foreign country &
the holder of the unlawfully acquired POTUS position.

IMO/FWIW