Helpful for criticizing this movie....
The Friends of Abe and other conservative groups were being leaned on by certain agencies in the Obama Administration. This movie was all about abuse of power, holding one idea -- communism -- up as the great boogie man of the day. However well Hoover may have meant, he rolled over the rights of people once he'd developed that single-minded hatred. Obama also had a thin-skin and went after anyone who criticized him, just as Hoover did.
I think this might be what this Republican filmmaker was hinting at.