If nothing else, the humiliations of the Secret Service had succeeded in bringing together two warring parties just one month before the midterm elections, as congressional leaders joined in rare agreement on Wednesday in calling for an independent investigation and demanding Pierson's ouster.

"The more we discover, the clearer it becomes that the Secret Service is beset by a culture of complacency and incompetence," House Speaker John Boehner said in a statement. The Ohio Republican voiced support for a proposal from Representative Michael McCaul for a "top-to-bottom, independent review of the agency."

Boehner's statement came a day after Pierson inspired little confidence among lawmakers with her appearance before the House oversight committee. Pierson struggled to explain how a knife-wielding Iraq War veteran could dash through an unlocked front door and deep into the White House after jumping a fence on Pennsylvania Avenue on Sept. 19. She also faced withering criticism over an incident before her tenure, in which the Secret Service did not realize for several days that a gunman had hit the White House with seven bullets from a semiautomatic rifle in 2011.

Topping off a dreadful day for Pierson, news broke hours after her testimony that yet another security breach occurred in September when the Secret Service allowed an armed contractor with a violent criminal history to ride an elevator, without authorization, with the president during a visit to the CDC headquarters in Atlanta.

In what may have been the final straw for the president, Earnest acknowledged that the White House was not aware of the elevator incident until shortly before news outlets reported it on Tuesday.

Pierson had taken "full responsibility" for the fence-jumping incident and vowed not to let it happen again, but her dispassionate demeanor frustrated lawmakers across the political spectrum.

The top Democrat on the committee, Representative Elijah Cummings of Maryland, said Wednesday morning on MSNBC's Morning Joe that he was so disturbed by her testimony that he couldn't sleep. "I’ve come to the conclusion that my confidence and my trust in this director, Ms. Pierson, has eroded," Cummings said, "and I do not feel comfortable with her in that position." Cummings later clarified in a Twitter post that he was not calling on Pierson explicitly to resign, but the damage of his statement was done.

Representative Nancy Pelosi, the House Democratic leader, offered no backing for Pierson at a press conference in the Capitol, saying she would support Cummings's judgement if he thought the director should go. Other lawmakers calling for Pierson's ouster following the hearing included Representative Jason Chaffetz of Utah, a senior Republican on the oversight committee, and Senator John McCain.