What is the republicans role in Benghazi?

There's something about the Benghazi mess that is clear to me. Republicans are trying to make a scandal out of a terrorist attack. But what if it wasn't just a terrorist attack? Why have the Republicans been having fits over it? Republicans doth protest too much. This is a big red flag. Is there something they don't want us to know?

I always thought the way Benghazi worked out and the timing was suspicious. Romney seemed a little too confident about victory, particularly over the summer. Benghazi happened before Romney received security briefings. Romney's response was over the top. Then the republicans started hearings before the election with the expectation they would find something. After that, Romney took shots at Obama about Benghazi during the debate and got crushed. But again, he behaved like he knew something.

I think the republicans are creating a smokescreen to cover their own role in the Benghazi mess.