Politicians love few things better than a scandal to trip up their opponents, and Republicans hope last year's fatal attack on U.S. diplomats in Libya will do exactly that to Hillary Rodham Clinton and other Democrats.
History suggests it might be a tough lift. The issue is complex, the next presidential election is more than three years away, and a number of reports and officials have disputed criticisms of Clinton's role when she was secretary of state.
Still, Republicans and conservative talk hosts are hammering away at Clinton's and the Obama administration's handling of the 8-month-old tragedy. A daylong House Oversight Committee hearing Wednesday starred three State Department officials invited by Republicans.
Security was poorly handled in Benghazi, Libya, they said, and administration officials later tried to obscure what happened.
Clinton, seen by many as the early Democratic favorite for president in 2016, generally drew strong reviews for her four-year stint as secretary of state. Her darkest moment was the Sept. 11, 2012, attack on the U.S. diplomatic mission in Benghazi.
Ambassador Chris Stevens and three other Americans were killed. Top administration officials initially said the attackers were spontaneous protesters, angry about an anti-Islamic video. But they later acknowledged the attackers were well-equipped terrorists acting under plans.
A major independent inquiry largely absolved Clinton of wrongdoing.
The findings incensed many Republican leaders and conservative news outlets, who portray Benghazi as a simmering scandal about to erupt.
The three officials testifying Wednesday offered little that has not been aired in previous congressional hearings. Afterward, Republicans all but acknowledged they're still seeking a knockout punch.
"This hearing is now over, but this investigation is not," said Rep. Darrell Issa of California, the hard-charging Republican chairman of the House committee. He urged "whistle-blowers" and "witnesses who have been afraid to come forward" to step up and "tell us your story, and we will make sure it gets public."
Republicans hope public anger over the Benghazi attacks and their aftermath will besmirch congressional Democrats in next year's midterm elections.
By late Wednesday, Democrats expressed confidence.
"The unsubstantiated Republican allegations about Benghazi disintegrated one by one," said Rep. Elijah Cummings of Maryland, the House committee's top Democrat. "There's no evidence of a conspiracy to withhold military assets for political reasons, no evidence of a cover-up."
Ethical lapses and even full-blown scandals have a mixed record of influencing U.S. elections. Watergate not only forced Richard Nixon from the White House in August 1974; it also triggered crushing losses for congressional Republicans in midterm elections three months later.
President Gerald Ford's pardon of Nixon may have ended any hope he had of defeating Jimmy Carter in 1976.
Other scandals, however, did far less political damage. The Iran-Contra affair of Ronald Reagan's second term and Bill Clinton's affair with Monica Lewinsky did not prevent either man's vice president from winning the popular vote in the next presidential election.
More recently, Virginia Democrats were crowing about news that Gov. Bob McDonnell - a potential GOP presidential contender - accepted large, unreported gifts from a businessman. A short time later, a Washington Post poll showed high approval ratings for McDonnell and scant public interest in the budding "scandal" that titillated the state's political elite.
Some Democratic campaign veterans say the Benghazi affair is too complex and too muddled to swing national elections next year and in 2016.
"The Republicans are pulling out the stops to manufacture a scandal, but it's not likely to stick on Hillary Clinton or Democrats in general," said veteran Clinton strategist Doug Hattaway.
Republicans seem determined to push on. House Speaker John Boehner of Ohio on Thursday asked President Barack Obama to direct the State Department to release internal emails, sent the day after the Benghazi attacks, regarding the deadly assault. "This is his chance to show his cooperation so that we can get to the truth of what happened in Benghazi," Boehner said.
On Wednesday, Democratic Rep. Mark Pocan of Wisconsin showed little concern about the larger impact on politics. "I don't think there's a smoking gun today," he told the House panel. "I don't think there's a lukewarm slingshot."
"It may not be a smoking gun or a warm slingshot," Republican Rep. Doug Collins said in the hearing's final hour. "But we have four dead Americans," and his constituents "are looking for the truth."