Well the Comey letter was the week immediately before the election, so the effect was mainly in the opening days of November. The proximity of the letter to the election left Clinton with no time to respond. A specious investigation early in October would probably backfire because it would leave enough time to create a counter-narrative.So does that mean the democratic attorney generals from California and New York will open up investigations into Trump as a retaliatory October surprise? (Isn‘t it that instead of November?)
Can‘t see that ending well for American Democracy.
I doubt Democratic state A-Gs would open up investigations of Trump designed purely to concoct a false scandal for unfair political gain - but Trump has form of doing just that, which is what makes Barr's control so dangerous. It wouldn't be so bad if it were the Obama administration, falling over itself in an effort not to create an appearance of interference.