The September 11 attacks on the U.S. diplomatic mission in Benghazi, Libya were back in the spotlight Wednesday with another House committee hearing on whether the Obama administration mishandled the tragic incident.

In the eight months since Benghazi, the debate about what happened in Benghazi has become deeply political, as Republicans continue to challenge the White House's actions during and after the attacks, which left four Americans, including U.S. Ambassador Chris Stevens, dead.

Neither side disputes that the Benghazi attacks were the tragic result of major failures at the State Department. An independent review released in December found that leadership and management deficiencies led to inadequate security at the U.S. Special Mission in Benghazi, despite repeated requests for additional security staffing from diplomatic personnel in Libya.

But that report has failed to mollify conservatives. Republicans insist that there are still unanswered questions about whether more could have been done to respond to the attacks, and whether the Obama administration actively tried to cover up its failures in the aftermath of the incident.

What follows is a breakdown of why conservatives are still hung up on Benghazi:

Security Failures In Benghazi: Republican critics continue to raise questions about why the State Department refused requests for more security personnel in Benghazi before the attacks, and whether the State Department and the Pentagon did everything possible to save American lives while the mission in Benghazi was under attack.

At Wednesday's hearing, State Department "whistleblower" Gregory Hicks, the deputy chief of mission in Libya during the attacks, said that he was frustrated when the U.S. military turned down a request to dispatch four Special Operations troops stationed in Tripoli to evacuate Americans in Benghazi.

Pentagon spokesman George Little said Wednesday that the military believes that there was nothing the four troops stationed in Tripoli could have done to assist in Benghazi, and that there were concerns about the security of American forces in Tripoli.

Hicks also told Congressional investigators that the Pentagon denied his request to fly fighter jets over the Benghazi attacks in the hopes of "scattering" the attackers.

The Pentagon has insisted that there was not enough time to deploy armed aircraft to Libya during the attacks in Benghazi.

The Alleged Cover-Up: The main problem conservatives have with Benghazi is not so much that it happened, but that they believe the Obama administration willfully tried to mislead the American public about it in the aftermath.

The focus here has been on U.N. Ambassador Susan Rice's appearance on Sunday talk shows just days after the attacks. Rice, working off the administration's unclassified talking points, characterized the attacks as a spontaneous demonstration over a video that disparaged Islam.

Even at the time, Rice's statements seemed to contradict the publicly available information about the attacks. Now, it is pretty clear that U.S. officials already knew at that point that the assault had been a terrorist attack.

Administration emails provided to House Republicans and further reported on by the Weekly Standard reveal that the initial unclassified talking points provided by the CIA did in fact include references to Al Qaeda, and noted that the agency had previously warned about the threat of Islamic extremists in Egypt and Libya.

But senior State Department officials expressed concerns about those talking points, arguing that they made it seem like the State Department had ignored CIA warnings. A senior White House official agreed that these concerns should be addressed, and the talking points that emerged from an interagency briefing were scrubbed of all references to terrorist attacks.

Washington Post fact-checker Glenn Kessler notes that a lot of this debate appears to be interagency squabbling. The CIA's initial draft was apparently designed to downplay the agency's substantial presence in Benghazi, and the State Department was likely reluctant to take all the blame.

Still, the question remains whether the Obama administration scrubbed the talking points and used the video red herring in order to cover up the fact that they failed to prevent a planned terrorist attack that killed four Americans on the anniversary of September 11.

Obama: The initial target of the Republican Benghazi probe was Obama, who was in the middle of a heated re-election campaign at the time of the attacks.

Conservatives note, correctly, that the administration had a powerful incentive to cover up their failings in Libya, as it would have undercut the media narrative about Obama's record on diminishing the Al Qaeda threat.

Conservatives have also raised questions about what Obama was doing during the eight hours that the Benghazi compound was under siege. Republicans note that then-Secretary of Defense Leon Panetta and Joint Chiefs Chairman Martin Dempsey have both said that they did not speak to Obama after an initial meeting when the attacks began.

As Ted Cruz put it in a National Review op-ed Wednesday, "neither the secretary nor the chairman knows if the president slept while our people were under attack."

Hillary Clinton: Now that the 2012 election is over, the GOP's focus has turned to Hillary Clinton, the leading Democratic contender in 2016 who played a starring role in the Benghazi controversy.

So far, Clinton has been relatively unblemished by Benghazi, even after clashing with Republican Senators at a Foreign Services Committee hearing in January.

But House Republicans believe that the independent review of Benghazi unfairly ignored her role in the State Department's failures leading up to the attack, and claim that Clinton needs to be held accountable for scaling back security in Benghazi.

At this point, it doesn't look like Benghazi will have much of an effect on Clinton's 2016 chances. But Republicans remain hopeful. In a Facebook post Tuesday, South Carolina Republican Sen. Lindsey Graham predicted that "the dam is about to break on Benghazi," and that Clinton could be a political casualty.