( CNN ) -- She 's mentioned by name only once in 85 pages , but former Secretary of State Hillary Clinton was back under a Republican microscope after a Senate report on the killings of four Americans in Libya . `` Sounds like the 2016 presidential race has now started , '' Sen. Dan Coats , R-Indiana , told CNN . Clinton leads early polls of potential Democratic presidential contenders . GOP leaders quickly focused their fire on her after the Senate Intelligence Committee concluded that the 2012 assault on the U.S. diplomatic outpost in Benghazi was `` likely preventable '' based on known security shortfalls and prior warnings . U.S . Ambassador Chris Stevens , State Department computer specialist Sean Smith and security contractors Glen Doherty and Tyrone Woods were killed in that attack . The Senate report spread the blame between the State Department and the intelligence community . State Department officials should have beefed up security in Libya 's second-largest city because of general warnings that U.S. personnel were at risk . The intelligence community could have flagged potential threats on `` extremist-affiliated social media , '' the report says . In addition , the report says intelligence officials inaccurately reported that a protest might have led to the attack , and took too long to correct the erroneous reports -- `` which caused confusion and influenced the public statements of policymakers . '' It follows a 2013 report by the State Department 's Accountability Review Board , which resulted in the reassignment of four State Department officials . But questions around security and intelligence as well as the changing explanation in the days that followed the attack -- which occurred in the heat of the 2012 presidential race -- led to allegations of a cover-up and repeated Republican calls for more explanation from the Obama administration . Wednesday 's report did little to quiet them . `` It raises questions that I think need to be answered before we can put this to rest , '' said Coats , one of five Republicans who blasted Clinton in a statement of `` additional views '' tacked onto the end of the report -- the only part of the document that identifies her directly . They argued that as secretary of state , Clinton bore `` ultimate accountability '' for security at the Benghazi mission , `` and we believe there should be a full examination of her role in these events , including on the night of the attacks . '' `` In this case , there are a lot of finger pointing elsewhere as to failures of the process and failures of the agency , et cetera , '' Coats said . `` But no one really has stood up and said , ' I take responsibility for this . ' That 's important . The American people want justice done here and closure to this issue . '' Clinton , who left office in February 2013 , has said she accepts responsibility for the Benghazi deaths . Speaking on condition of anonymity , a Clinton adviser told CNN , `` Four Americans lost their lives . We have never and will never approach this tragedy through the prism of politics . If others continue to do so for their own gain , they 're going to have to do it without us . '' But Sen. Lindsey Graham , R-South Carolina , told CNN that Clinton `` has to clear the air on Benghazi '' if she wants to be president . `` She has a lot of accomplishments . She 's a very accomplished woman . But , under her leadership , the consulate became a death trap , '' said Graham , who does n't sit on the Intelligence Committee . And Sen. John McCain , R-Arizona , said , `` The American people hold all of us accountable who are in responsibility . She should be held accountable . '' But comments like that drew a sharp response from the committee 's chairwoman , California Democrat Dianne Feinstein , on Thursday . In a statement issued by her office , Feinstein said claims that the report blames Clinton for the Benghazi deaths are `` patently false , '' and that the Republican addendum `` unfairly criticizes Secretary Clinton . '' Wednesday , Feinstein told CNN 's The Situation Room that `` it 's interesting that the first thing out of the box is something that 's political . '' And at the White House , spokesman Jay Carney criticized what he called `` a very politicized effort on this that has seen a lot of conspiracy theories floated , reported on as fact , and then debunked . '' `` Our interest is in getting those who are responsible , bringing them to justice , and taking the steps necessary to ensure that this kind of thing ca n't happen again or is far less likely to happen again , '' Carney said Thursday . But efforts to bring the perpetrators -- identified as members of a variety of Islamic militant groups , some affiliated with al Qaeda -- to justice have been frustrated by the lack of `` political incentive or will '' by Libyan authorities to prosecute those believed responsible , the Senate report states . In addition , it noted , up to 15 people who had assisted the probe have been killed since September 2012 , though it was n't clear if the deaths were related to the probe . CNN 's Elise Labott and Paul Courson contributed to this report .
NEW : Clinton adviser blasts `` the prism of politics '' around Benghazi . `` Sounds like the 2016 presidential race has now started , '' senator says . Senate committee finds Benghazi attack was likely preventable . Republicans blast Clinton in addendum to report ; committee leader calls that unfair .