The FBI has been politicized in a major way. This is actually not a new concept. But today, more things become revealed to the public than in past decades.
J. Edgar Hoover dominated the FBI for so long and was so entrenched in his position that nobody questioned to what extent he had weaponized the FBI as his own political tool. Much of what the FBI did certainly enhanced the security apparatus of the United States of America. But no historian today will argue that J. Edgar Hoover was not politically motivated to preserve his hold on his own power structure.
Today’s FBI should probably be turned around completely into a more transparent government body. But that is of course very challenging as the very nature of the FBI is one that handles covert information gathering programs in order to protect national security.
It is indeed a tricky business – one that will always be filled with overstepping the lines of legal and extralegal. There is no way around that. However, what should be done is a non-political body, ideally from the Judiciary, should be tasked with making sure that lines are not broken that will endanger national security by having any government body accrue too much power. Checks and balances that slow down but don’t strangle government agencies are a blessing for democracy and freedom.