Politically, a recommendation for indictment by the FBI would be almost as damaging as an actual indictment. And if the DOJ failed to pursue the recommendation for indictment, then Obama and his administration will be charged with the cover-up. Hence, the constitutional crisis. Something similar happened during Watergate, but the big difference was that the Reps in Congress supported pursuing charges. Today, the Dems will close ranks and blame the FBI for being partisan and interfering in the electoral process.
The reaction of the public remains to be seen,