The changeover to click-driven media certainly had a lot to do with it, but the media types (many of whom have the same relationship with the Clintons that Ahab had with the whale) were more than happy to help Republicans keep this "story" alive. Eric Boehlert at Media Matters:
So the fact that the national press, at the behest of Republicans, remains focused on Benghazi this week is somewhat amazing. But as the GOP's Benghazi production winds down, having had its reputation severely damaged in recent days, it's important to understand the central role the press has played over the last three years in keeping the partisan pursuit afloat.
The truth is there were obvious points over the last three years when the press could have, and should have, gotten on the Benghazi exit ramp:
*May 19, 2013: ABC News' Jonathan Karl was burned when his exclusive report regarding White House emails in the wake of the Benghazi attack turned out to be inaccurate. Karl, relying on a likely Republican source on Capitol Hill who relayed the emails' contents, accused the administration of having "scrubbed" vital information from the Benghazi talking points used in the wake of the attack. Karl's report quickly ignited a new round of Republican outrage over the administration's handling of the attack. But a full reading of the emails showed Karl's claims were clearly misleading.
*October 27, 2013: CBS' 60 Minutes aired a Benghazi exclusive, featuring Dylan Davies, a private security guard who claimed to have scaled a 12-foot wall at the U.S. diplomatic facilities in Benghazi the night of the attack, and who claimed the Obama administration had failed to properly protect Americans. But it turned out the story was fabricated by Davies, who had earlier given the FBI a completely different account of his whereabouts the night of the Benghazi attack. Widely criticized for being duped by a story that Republican operatives cheered, CBS was forced to air an apology for the botched report, and 60 Minutes correspondent Lara Logan left the show for seven months.
*November 22, 2014: The House Intelligence Committee released its comprehensive Benghazi findings and concluded "The CIA and the military acted properly in responding to the 2012 attack on a U.S. diplomatic compound in Benghazi, Libya," according to the Associated Press. "Among other findings, the report concluded that the administration did not delay in dispatching a CIA rescue team to the attack site, that there was no missed opportunity to stage a military rescue, and that nobody in the government issued a 'stand down' order to halt a planned rescue," CBS reported. The inquiry produced so little bad news for the administration that Benghazi dead-ender Sen. Lindsey Graham (R-S.C.) denounced the House findings as being "full of crap."↓ Story continues below ↓
Looking back, I'd add another key moment when the press could have rightfully concluded that the Republicans' Benghazi inquisition wasn't going to produce much of substance, and that was January 23, 2013, when Clinton first testified about the events.
At the time, the State Department's Accountability Review Board had already issued its report on the attack. It detailed agency shortcomings and made recommendations, which Clinton accepted. There were no major revelations during Clinton's 2013 testimony that suggested Republicans would be able to actually substantiate any scandalous claims against her or the administration.
And sure enough, 33 months later that remains the case. Yet the press has spent way too much of that time wallowing in Benghazi.
According to a Nexis search, here's how many times, since January 23, 2013, that each of the following news organizations have published content that mentioned "Benghazi" at least three times (note: Nexis results for some outlets include things like editorials and letters to the editor):
Washington Times: 501
Washington Post: 380
New York Times: 306
Chicago Tribune: 210
New York Post: 132
USA Today: 107