Am I...agreeing with Boiled Goose? Lord, these are the times....
Lets just settle something. When Comey sent that letter, he knew what he was doing. Unless he was a fucking moron, he knew what House Republicans would do with the news that the FBI was reopening the Clinton email investigation, especially since this wasn't info they were required to keep quiet (so it being a private letter doesn't matter one bit). So, again, unless Comey is a total fucking dumbass (which...), when he sent that letter he knew he was acting in a way that would greatly benefit one party over the other.
Regardless of what his intentions were, his actions WERE partisan.
That doesn't mean he's in Trump's pocket, or even that he was trying to help him. What I believe, and what a lot of people seem to believe, is that he allowed his own ego and sense of righteousness back him into a corner. Again, he wanted to be the maverick.
He just should have never opened the door to start with.