The House has oversight jurisdiction about everything that goes on within all federal agencies - CIA inclusive. By law, The House Oversight Committees which oversee the CIA can subpoena any agency employee while conducting an official investigation. If the employee fails to show up or answers the committees questions, he can be held in contempt of Congress. If it is shown that the employees boss or management threatened or encouraged him/her to not comply, those people can be held in Contempt as well as face charges of obstructing Congress.
The GOP leadership obviously is either terrified of getting on Obama's and the MSM's bad-side, or they themselves are part of the cover up. We are talking about criminal acts. Why is the GOP so passive?