<Trump merely walked through the cracks created under Obama.>

Which were dependent on the GWB administration (forced renditions, torture prisons), the Reagan administration (Iran-Contra etc), the Nixon Administration (Watergate etc), FDR's admin (concentration camps), on and on and on.

The expansion of Presidential power is non-partisan. Congress would be the logical counterbalance but other than in fits and starts has generally abdicated this role to the SCOTUS which has now been captured by believers in the unitary Presidency.