Jazz....if you want to make this solely about Spitzer, thats fine.
I think there is a much broader issue at play that gets to the question of the OP:
Is this the best use of the FBI's Resources if there is a real War on Terror?
This administration has made public corruption the highest priority for investigation after national security and above violent crime covered by federal law, crimes against children, civil rights violations, and other white collar crime.
Then went on to actively initiate or pursue investigations against Democrats at a far greater rate than Republicans.
There is compelling evidence that the firing of the US attorneys is directly related to the unwillingness of some of those attorneys to pursue public corruption when none existed or were pressured to expend an inordinate amount of resources to target Democrats at the expense of other investigations.
The system of justice is undermined even by a perception of such politicization and it places a cloud over every investigation, including the Spitzer case.