You really need to take a course in remedial reading comprehension, dude. I'm not at all sure that there is a conspiracy or any egregious acts (as opposed to simple screw-ups) over which to conspire. I'm saying that for Republicans to come out ahead:
1. Something damaging to Obama and/or Hillary (assuming she runs in 2016) had to have happened which is known to some people.
2. If #1 is true, the Republicans have to find out about it.
3. If #1 & #2 are satisfied, the Republicans need some way to convince the public. Given that the public has no more reason to trust the Pubbies than the Dems and Obama, that requires eyewitnesses or persons otherwise having knowledge and provenance.
4. As these people are under Obama's chain of command, he would do everything reasonable to ensure they do not come forward.
5. If someone does come forward, the public would have no way of knowing whether he is telling the truth. Even people who are not politicians sometimes lie for political (or other) reasons. Therefore at least two or three would be needed unless it was someone of unimpeachable integrity as perceived by the public.
6. If #5 happened, the Obama attack machine would go into action to discredit the accusations.
To sum it all up, for the Republicans to come out ahead:
Obama and/or Hillary had to do something illegal, immoral or otherwise unethical; Republicans have to learn what it is; Republicans have to have witnesses with sufficient gravitas and provenance to be believed; and Republicans have to overcome the Democrat effort to discredit the claims.
Nothing about this assumes that there is anything to cover up. (In fact, perception being reality in politics that is arguably the least important element and the only one which could conceivably fail, yet leave the Pubbies coming out ahead on Benghazi by selling the notion that there is something to cover up when there is not.) All I'm saying is that IF there is something damaging to Team Obama, the Republicans would still face an uphill battle coming out on top and are unlikely to succeed. Since I see nothing particularly damaging to Obama or even Hillary, and I can see the uphill battle the Pubbies would face if there is something damaging, I see no way the Republicans come out ahead on Benghazi.
One could even make the argument that the Republicans stand a better chance of damaging Obama if there is no basis, for if there is information that is personally damaging Obama would surely expend a lot more energy keeping the eyewitnesses away from Republicans than if this is a knee-jerk reaction that nothing they say can help him and it might possibly hurt him whether or not he did anything wrong, so it's best these people are not accessible to Republican Congressional investigators.