The latest round of Capitol Hill hearings picking apart the U.S. response to the attack on its diplomatic mission in Benghazi last September has arrived. It has arrived with promises from  Republicans on Darrell Issa's House committee on oversight and reform that big things will be revealed at its 11:30 a.m. Eastern session (titled "Benghazi: Exposing Failure and Recognizing Courage"). It has arrived with three witnesses, one of whom will say his call for fighter jets from Tripoli went ignored that fateful night and that the Obama administration misled the public after — and at least one of the others will delve back into those fateful talking points and the alleged State Department conspiracy that still, nearly eight months later, brings former Secretary of State Hillary Clinton back into this whole thing. Oh, and there will be surprises. All of this has conservatives in the punditocracy and the other halls of Congress talking "additional hearings" and about how a "dam is about to break" and even about "impeachment." But first, here's an in-depth look at the day ahead:

The State Department Whistleblower Witnesses

Gregory Hicks, former deputy chief of mission at the U.S. Embassy in Libya

Eric Nordstrom, former lead security official for the State Department in Libya

Mark Thompsondeputy coordinator for operations in the State Department's counterterrorism bureau

Why Their Testimony Has Conservatives Excited

No offense to Mr. Nordstrom, but the two testimones being hyped and drawing massive attention from Fox News to Washington and well beyond are those of Hicks and Thompson, which are supposedly going to prove what Republicans Senators John McCain, Kelly Ayotte, and Lindsey Graham have been saying since November: that Secretary of State Hillary Clinton and President Obama did not do all they could do to stop the attack and then purposely deceive the public about the attacks.

"I think her [Hillary Clinton] dereliction of duty and her lack of leadership should preclude her from holding any office," Senator Rand Paul said during a speech to Missouri Republicans Tuesday morning, referring to Benghazi and very much setting the table for today's session. 

Why Hicks Is Important

Hicks, a 22-year foreign services diplomat, was the highest ranking official in Libya during the attacks on September 11, 2012 (he was some 600 miles away in the capitol of Tripoli, not Benghazi, at the time). Hicks is also the first ground-level witness to speak about the attacks in the multiple rounds of Congressional hearings. And the two biggest parts of his time under oath today, according to prepared testimony and expected questioning, will center around calling the attack a "terror attack" in the first few minutes — and, tactically, that the Obama administration did not grant his request to scramble at least one F-16 jet from Tripoli to the sieged compound, a move Hicks believes would have scared off attackers and possibly saved some lives. Hicks had testified last month regarding the matter of a fighter plane strategy, and excerpts of his opening statement were released on Monday night in advance of the hearings. Here, from CBS, is the thrust of it:

"I believe if we had been able to scramble a fighter or aircraft or two over Benghazi as quickly as possible after the attack commenced, I believe there would not have been a mortar attack on the annex in the morning because I believe the Libyans would have split. They would have been scared to death that we would have gotten a laser on them and killed them," Hicks testified. Two Americans died in the morning mortar attack.

In his April testimony before investigators associated with the same House oversight committee, Hicks said that a Africa Command special-ops chief and a team were ready to board a C-130 to Benghazi, but were told to sound down, CBS reports.

There have been two arguments against the move to send a jet into the air over the compound. The first: a fighter jet would have caused more confusion. "Gen. Carter Ham, the head of the military's Africa Command, has said American F-16 fighters in Europe were not on alert the night of the Benghazi assault, and would not have been useful anyway in a confused situation in a major Arab city," report The New York Times's Jeremy Peters and Eric Schmitt.

And CBS reports that the Obama administration had argued that no aircraft would have gotten there in time to do any good: 

Obama administration officials have insisted that no military resources could have made it in time. A White House official told CBS News that, at the start of the attack, Chairman of the Joint Chiefs Martin Dempsey and Defense Secretary Leon Panetta "looked at available options, and the ones we exercised had our military forces arrive in less than 24 hours, well ahead of timelines laid out in established policies."

The other part big piece of Hicks's testimony will center on calling Benghazi a terror attack. According to interviews with investigators that were shared with Face the Nation, Hicks said:

I thought it was a terrorist attack from the get-go. I think everybody in the mission thought it was a terrorist attack from the beginning.

As we've heard in the last several months, there have been myriad allegations that the Obama administration purposely misled the public about the nature of the attacks because ambassador Susan Rice said on a couple of Sunday morning talk shows that the administration initially believed that, to the best of its knowledge, the attack was part of a protest. Rice had told Face the Nation on the Sunday following the attacks:

But based on the best information we have to date, what our assessment is as of the present is in fact what began spontaneously in Benghazi as a reaction to what had transpired some hours earlier in Cairo where, of course, as you know, there was a violent protest outside of our embassy ... But soon after that spontaneous protest began outside of our consulate in Benghazi, we believe that it looks like extremist elements, individuals, joined in that– in that effort with heavy weapons of the sort that are, unfortunately, readily now available in Libya post-revolution. 

[...]

I mean I think it’s clear that there were extremist elements that joined in and escalated the violence. Whether they were al Qaeda affiliates, whether they were Libyan-based extremists or al Qaeda itself I think is one of the things we’ll have to determine.

Why Thompson Is Important

Well, first off, Thompson still has his job, so he's something of a true whistleblower. He's the acting deputy assistant for operations for the Counterterrorism Security Group at State, and as Fox News reported on Monday, his testimony is expected to insist that Clinton willfully blocked out his department's involvement and that he has received threats State Department regarding his potentially damaging testimony.

As CBS News reported, we know that the Obama administration "did not convene its top interagency counterterrorism resource, the Counterterrorism Security Group." The gist of that under oath, according to Fox's James Rosen, will play out something like this: "Clinton and a key aide effectively tried to cut the department's own counterterrorism bureau out of the chain of reporting and decision-making." And that's supposedly damaging in light of the administration scrubbing al Qaeda references from talking points following the attacks:

Documents from the State Department, the Central Intelligence Agency and the National Security Council, first published in the May 13 edition of "The Weekly Standard," showed that senior officials from those agencies decided within days of the attacks to delete all references to Al Qaeda's known involvement in them from "talking points" being prepared for those administration officers being sent out to discuss the attacks publicly.

The administration later acknowledged that there had been no such protest, as evidence mounted that Al Qaeda-linked terrorists had participated in the attacks. The latter conclusion had figured prominently in the earliest CIA drafts of the talking points, but was stricken by an ad hoc group of senior officials controlling the drafting process. Among those involved in prodding the deletions, the documents published by "The Weekly Standard" show, was State Department spokeswoman Victoria Nuland, who wrote at one point that the revisions were not sufficient to satisfy "my building's leadership."

The administration's alleged purposeful striking of those al-Qaeda references could be — indeed, has already been — interpreted as a cover-up over an issue that the Obama administration has repeatedly said it's taken care of. It's the kind of conspiracy that has sent conservative pundits like Jennifer Rubin into a euphoric tizzy, others like Michelle Malkin into full-on defensive mode, and fringe Republican congressman like Rep. Steve King into  ten-times-bigger-than-Watergate-and-Iran-Contra-combined hysterics.

Thompson is also alleging that the State Department has tried to intimidate him from giving his testimony: 

Thompson's lawyer, Joseph diGenova, a former U.S. attorney, has further alleged that his client has been subjected to threats and intimidation by as-yet-unnamed superiors at State, in advance of his cooperation with Congress.

What Conservative Are Really, Really Excited About

With the Republican party pulling out all the stops to move beyond the crushing 2012 election, it looks like the Republican-controlled House — and potential candidates in the Senate — are aligning against Clinton's all-but-certain 2016 run in the form of the endless Benghazi scandal. As if the statements from Paul and Lindsey "The Dam Is About to Break" Graham weren't enough, Chris Stirewalt, the politics editor at Fox News — which has featured blanket coverage of Benghazi — has a piece headlined "Clinton’s Candidacy May Ride on Benghazi" and Paul's "dereliction of duty" statement. Stirewalt writes: 

The big story is Benghazi, because it involves the frontrunner, former Secretary of State Hillary Clinton. And the implications are serious ... In the best telling of events for Clinton, she sidestepped the incident, allowing Obama intimates to take the fall. In the worst telling, Clinton was part of decisions that left Americans vulnerable, denied them assistance under fire and then elided when the time came to go public about the attack. 

And that makes it hard to tell whether Republicans are more interested in really achieving clarity and information about how to prevent another deadly attack on an American diplomatic outlet, or if they're more interested in how to stop momentum from a political opponent. You can watch the proceedings on C-SPAN 3 to find out.