The lesson of Comey's testimony is do not ever under-estimate Republican senators.
By the end of it, they had Comey:
-admitting a personal bias against Trump before he took office,
-admitting to felony leaking,
-calling out the New York Times for fake news,
-inculpating Loretta Lynch in obstruction, and possibly Bill Clinton too, and
-admitting that the FBI never verified the Dem's claims about Russian hacking.

Masterful.