Continued from page 1

Committee Chairman Darrell E. Issa, California Republican, said his goal was simple: “Make certain that our government learns the proper lessons from this tragedy so that it never happens again.”

He also lashed out at Democrats, saying that time and again over the past eight months they have “sat silent” while Republicans sought answers from an administration that “has not been cooperative.”

Mr. Cummings shot back that Mr. Issa was willfully leveling “false accusations” at the White House, engaging in a “full-scale media campaign that is not designed to investigate what happened in a responsible and bipartisan manner, but rather to launch unfounded accusations and to smear public officials.”

Things got particularly heated on the subject of Republican accusations that the White House engaged in foul play with regard to “talking points” given to U.N. Ambassador Susan E. Rice, who appeared on several television talk shows about a week after the Benghazi attacks.

Lawmakers on both sides of the aisle cued up video clips of statements by top intelligence and State Department officials — including tape of Mrs. Clinton’s question during her own testimony to Congress in January, when she asked if it mattered whether the attack was spurred by an anti-Islamic video or was an orchestrated terrorist assault.

“The fact is we had four dead Americans. Was it because of a protest or was it because of guys out for a walk one night who decided they’d go kill some Americans?” she said. “What difference at this point does it make? It is our job to figure out what happened and do everything we can to prevent it from ever happening again.”

In every case, the lawmakers appeared eager to goad Mr. Hicks into delivering a reaction that might prove the administration’s guilt or innocence — and each time, they came up short.

“I don’t know anything about the development of those talking points,” Mr. Hicks said.