A former State Department staffer who helped set up the email server in former Secretary of State Hillary Rodham Clinton's home formally asserted his Fifth Amendment right against self-incrimination Thursday rather than answer questions before a Republican-led House committee.

The committee's Republican and Democratic members got into a public spat over whether Bryan Pagliano's closed-door appearance before the House Select Committee on Benghazi was necessary. His lawyer last week had told the committee that Pagliano would not testify.

"Political theater" is how Rep. Elijah Cummings of Maryland, the committee's top-ranking Democrat, described the meeting. "Mr. Pagliano's testimony has nothing to do with the Benghazi attacks and everything to do with Republicans' insatiable desire to derail Secretary Clinton's presidential bid," Cummings said in a statement. It came on a day that the committee announced it will be interrogating longtime Hillary Clinton aide Huma Abedin sometime before Oct. 22, when Clinton herself is set to appear. After defending her use of personal email for State Department business, the Democrat this week apologized. Controversy over her unusual communications system has taken a toll on her poll numbers.