I outsource to Paul Waldman at The American Prospect, because he nails it oh so rightly:

If you're looking at the Republican harumphing over Benghazi and asking yourself, "Why are we supposed to be so mad about this again?" you're not alone. Let's review: There was an attack on our consulate that killed four Americans, including our ambassador. Amid confusing and contradictory reports from the ground, President Obama waited too long to utter the magic incantation, "Terrorism, terrorists, terror!" that would have … well, it would have done something, but it turns out that he did say "terror," so never mind that. But that's not the real scandal! The real scandal is that Susan Rice went on television soon after and amid all kinds of "based on the best information we have"s and "we'll have to see"s, said one thing that turned out not to be the case: that after the protests in Cairo, there was some kind of copycat protest in Benghazi, which was then "hijacked" by extremist elements using heavy weapons to stage an attack.

A sane person might say, OK, she was obviously given some incorrect information at that time, but it's not a particularly meaningful deception. As people have been pointing out for weeks now, it's not as though not using the word "terror" or saying there was a protest before the attack gave the White House some enormous political advantage. If you're going to have a cover-up, there has to be something you're covering up.

But now, some Republicans, particularly John McCain and Lindsay Graham, are essentially saying that this horrifying cover-up was quite possibly the greatest crime in the history of the United States government, and if we're going to get to the bottom of it nothing short of a select committee—a "Watergate-style committee," as it is being referred to by reporters—will do. Who knows what it might uncover? Were there CIA whistleblowers whose bodies are now lying at the bottom of the Potomac? Was David Petraeus being blackmailed? Are William Ayers and Jeremiah Wright involved? Did Susan Rice fly to Tripoli, have a steamy liaison with a clone of Ayman al-Zawahiri created in a secret underground laboratory, then go to Benghazi where she personally killed Ambassador Chris Stevens with a hat pin? We won't know unless we spin this out into a multi-week story!

So what's going on here? I can sum it up in two words: scandal envy. Republicans are indescribably frustrated by the fact that Barack Obama, whom they regard as both illegitimate and corrupt, went through an entire term without a major scandal. They tried with "Fast and Furious," but that turned out to be small potatoes. They tried with Solyndra, but that didn't produce the criminality they hoped for either. Obama even managed to dole out three-quarters of a trillion dollars in stimulus money without any graft or double-dealing to be found. Nixon had Watergate, Reagan had Iran-Contra, Clinton had Lewinsky, and Barack Obama has gotten off scott-free. This is making them absolutely livid, and they're going to keep trying to gin up a scandal, even if there's no there there. Benghazi may not be an actual scandal, but it's all they have handy.

Republicans aren't doing themselves any favor by being the Boy Who Cried Wolf.  If, at some point, there is a legitimate scandal, then when Fox News and the GOP starts jumping up and down with their hair on fire, screaming, "It's a -Gate!  It's a -Gate!", the rest of the country will yawn.