Progressives / liberals / democrats on this board are getting more irritable about Libya. Therefore I conclude Republican pressure on the issue is the correct political play. Democrats, including the current president, played politics with the Iraq war, and went on a relentless attack of Scooter Libby, who was ultimately cleared of wrong doing. Remember "Bush Lied, People Died"? Game theory insists that Republicans return the favor now.
If the Democrats in Congress want to play proper statesmen on the next issue, Republicans should be forgiving and go along, but they have to return hard ball partisan politics with the same fervor, or be subject to the downside of Democratic hard ball, without the upside of Republican hard ball.
That being said, I think this issue deserves direct oversight. The president sent his people out to lie (we can now say it was an outright lie - CIA knew within 24-72 hours that attack was terrorist with probable AQ connections, yet Rice was on shows saying "video" 5 days later.) There are a lot of unanswered questions, including: why were Patreus' talking points changed and by whom? (Speculation: OfA staffers had access to material they weren't cleared for and changed the talking points for political campaign reasons. This would be a serious violation of security rules AND explain how NYT had detailed break down of events so soon. Just speculation, but probably enough to justify strict oversight and investigation into the matter.) Additionally our inability to meet security requests of our diplomatic leadership at State (we know 100% that this had been requested for months and there is speculation that the site was a black ops site, so request should have been taken very seriously) is a matter for congressional oversight. The Senators basically can only grandstand since the president's party controls the Senate, any oversight and investigation is likely to be a sham (same would be true if the letters were switched) all the Senators can do is rally public support to bring populist political pressure to enable oversight. The choice of McCain makes sense - his credibility with Republicans isn't great, but he's seen as having both integrity and foresight from both parties on national defense.