Democratic groups on Tuesday launched efforts to defend former Secretary of State Hillary ClintonHillary Rodham ClintonScarborough: Missed opportunities in Trump’s inauguration speech Chelsea Clinton: Let Barron Trump be a kid Juan Williams: Ethics cloud hangs over Trump MORE one day ahead of the House Select Committee on Benghazi's first public hearing.
The groups see the investigation as intended to tarnish Clinton, a likely Democratic presidential contender.
"Republicans have no credibility on this issue and are wasting taxpayer dollars on these sham hearings to ask questions that have already been answered," the groups said in the statement. "All for political gain: both to drive up their base turnout in 2014 and to go after Secretary Clinton for 2016."
The groups also pointed to the Accountability Review Board (ARB) Clinton set up as evidence there is no need for further hearings.
"By deciding to implement the 29 ARB recommendations, Secretary Clinton has done more to get to the bottom of Benghazi, and prevent it from happening again, than any of those who will attack her as part of these sham hearings," the groups said.
The chairman of the committee, Rep. Trey GowdyTrey GowdyCongress asserts itself GOP rep says media is 'blurring' fact and opinion Oversight panel demands answers on Pentagon waste report MORE (R-S.C.), has cast doubt on the ARB, saying "there's no objectivity" because it was appointed by Clinton.
The Wednesday hearing will center on the implementation of the ARB recommendations. [Read witness list.]
Media Matters For America, another pro-Clinton group, launched a guide to the committee called "All Questions Answered."
While not solely about defending Clinton, Democrats on the committee also held a press conference on Tuesday morning and introduced an "Asked and Answered" website providing responses to questions they say have already been answered.
The Republican majority on the committee later hit back at the Democrats and defended the investigation on Tuesday.
“As Chairman Gowdy has said, he is willing to risk answering the same question twice rather than risk it not be answered at all," communications director Jamal Ware said in a statement. "Since all documents responsive to Congressional inquiries into the Benghazi terrorist attack have not been produced, it is fair to say that not all questions have been asked and answered."
Gowdy has said the investigation should be over by the end of 2015.